1
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Chao FA, Byrd RA. Existence of Singularities in NMR Relaxation Dispersion Profiles: Implications for Hidden Dynamics. J Am Chem Soc 2024; 146:24467-24475. [PMID: 39172084 DOI: 10.1021/jacs.4c06720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
It is common for NMR relaxation dispersion experiments to suggest an absence of dynamics despite anecdotal indications of conformational dynamics. We explore the potential explanations and approaches to this conundrum. Some inconsistencies have been observed between two relaxation dispersion experiments, Carr-Purcell-Meiboom-Gill (CPMG) and adiabatic relaxation dispersion experiments, in recent dynamic studies of different biomolecules. Theoretical analyses show that such seemingly paradoxical results might come from a complex exchange topology that is concealed by the application of the simple two-site exchange model for interpretation of the relaxation dispersion data. Scenarios are explored and revealed in which the presence of complex millisecond conformational exchange could suppress the amplitude of CPMG relaxation dispersion profiles, even when the exchange rates are within the detectable range of the experiments. With experimental errors, the suppressed relaxation dispersion profiles could lead to the conclusion of "no millisecond conformational exchange". However, such hidden dynamics can potentially be detected by adiabatic relaxation dispersion experiments. Finally, we demonstrate some advantages of adiabatic relaxation dispersion experiments over conventional relaxation dispersion experiments and a simplified computational approach to analyze the adiabatic relaxation dispersion profiles.
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Affiliation(s)
- Fa-An Chao
- NCI RAS Initiative, Cancer Research Technology Program, Frederick National Laboratory for Cancer Research, Leidos Biomedical Research, Frederick, Maryland 21701-4907, United States
| | - R Andrew Byrd
- Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, Maryland 21702-1201, United States
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2
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Hou XN, Song B, Zhao C, Chu WT, Ruan MX, Dong X, Meng LS, Gong Z, Weng YX, Zheng J, Wang J, Tang C. Connecting Protein Millisecond Conformational Dynamics to Protein Thermal Stability. JACS AU 2024; 4:3310-3320. [PMID: 39211624 PMCID: PMC11350723 DOI: 10.1021/jacsau.4c00649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/19/2024] [Revised: 08/07/2024] [Accepted: 08/07/2024] [Indexed: 09/04/2024]
Abstract
The stability of protein folded states is crucial for its function, yet the relationship with the protein sequence remains poorly understood. Prior studies have focused on the amino acid composition and thermodynamic couplings within a single folded conformation, overlooking the potential contribution of protein dynamics. Here, we address this gap by systematically analyzing the impact of alanine mutations in the C-terminal β-strand (β5) of ubiquitin, a model protein exhibiting millisecond timescale interconversion between two conformational states differing in the β5 position. Our findings unveil a negative correlation between millisecond dynamics and thermal stability, with alanine substitutions at seemingly flexible C-terminal residues significantly enhancing thermostability. Integrating spectroscopic and computational approaches, we demonstrate that the thermally unfolded state retains a substantial secondary structure but lacks β5 engagement, recapitulating the transition state for millisecond dynamics. Thus, alanine mutations that modulate the stabilities of the folded states with respect to the partially unfolded state impact both the dynamics and stability. Our findings underscore the importance of conformational dynamics with implications for protein engineering and design.
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Affiliation(s)
- Xue-Ni Hou
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Bin Song
- Shanghai Institute of Virology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Chang Zhao
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei, Wuhan 430071, China
| | - Wen-Ting Chu
- State Key Laboratory of Electroanalytical Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China
| | - Mei-Xia Ruan
- Beijing National Laboratory for Condensed Matter Physics, CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Xu Dong
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei, Wuhan 430071, China
| | - Ling-Shen Meng
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
| | - Zhou Gong
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei, Wuhan 430071, China
| | - Yu-Xiang Weng
- Beijing National Laboratory for Condensed Matter Physics, CAS Key Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China
| | - Jie Zheng
- Shanghai Institute of Virology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jin Wang
- Department of Chemistry and Physics, Stony Brook University, Stony Brook, Newyork 11794-3400, United States
| | - Chun Tang
- Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China
- Center for Quantitative Biology, PKU-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
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3
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Cai M, Agarwal N, Garrett DS, Baber J, Clore GM. A Transient, Excited Species of the Autoinhibited α-State of the Bacterial Transcription Factor RfaH May Represent an Early Intermediate on the Fold-Switching Pathway. Biochemistry 2024; 63:2030-2039. [PMID: 39088556 PMCID: PMC11345854 DOI: 10.1021/acs.biochem.4c00258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/03/2024]
Abstract
RfaH is a two-domain transcription factor in which the C-terminal domain switches fold from an α-helical hairpin to a β-roll upon binding the ops-paused RNA polymerase. To ascertain the presence of a sparsely populated excited state that may prime the autoinhibited resting state of RfaH for binding ops-paused RNA polymerase, we carried out a series of NMR-based exchange experiments to probe for conformational exchange on the millisecond time scale. Quantitative analysis of these data reveals exchange between major ground (∼95%) and sparsely populated excited (∼5%) states with an exchange lifetime of ∼3 ms involving residues at the interface between the N-terminal and C-terminal domains formed by the β3/β4 hairpin and helix α3 of the N-terminal domain and helices α4 and α5 of the C-terminal domain. The largest 15N backbone chemical shift differences are associated with the β3/β4 hairpin, leading us to suggest that the excited state may involve a rigid body lateral displacement/rotation away from the C-terminal domain to adopt a position similar to that seen in the active RNA polymerase-bound state. Such a rigid body reorientation would result in a reduction in the interface between the N- and C-terminal domains with the possible introduction of a cavity or cavities. This hypothesis is supported by the observation that the population of the excited species and the exchange rate of interconversion between ground and excited states are reduced at a high (2.5 kbar) pressure. Mechanistic implications for fold switching of the C-terminal domain in the context of RNA polymerase binding are discussed.
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Affiliation(s)
- Mengli Cai
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Nipanshu Agarwal
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - Daniel S. Garrett
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - James Baber
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
| | - G. Marius Clore
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland 20892-0520, United States
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4
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Kalaj BN, La Clair JJ, Shen Y, Schwieters CD, Deshmukh L, Burkart MD. Quantitative Characterization of Chain-Flipping of Acyl Carrier Protein of Escherichia coli Using Chemical Exchange NMR. J Am Chem Soc 2024; 146:18650-18660. [PMID: 38875499 PMCID: PMC11299499 DOI: 10.1021/jacs.4c05509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2024]
Abstract
The acyl carrier protein of Escherichia coli, termed AcpP, is a prototypical example of type II fatty acid synthase systems found in many bacteria. It serves as a central hub by accepting diverse acyl moieties (4-18 carbons) and shuttling them between its multiple enzymatic partners to generate fatty acids. Prior structures of acyl-AcpPs established that thioester-linked acyl cargos are sequestered within AcpP's hydrophobic lumen. In contrast, structures of enzyme-bound acyl-AcpPs showed translocation of AcpP-tethered acyl chains into the active sites of enzymes. The mechanistic underpinnings of this conformational interplay, termed chain-flipping, are unclear. Here, using heteronuclear NMR spectroscopy, we reveal that AcpP-tethered acyl chains (6-10 carbons) spontaneously adopt lowly populated solvent-exposed conformations. To this end, we devised a new strategy to replace AcpP's thioester linkages with 15N-labeled amide bonds, which facilitated direct "visualization" of these excited states using NMR chemical exchange saturation transfer and relaxation dispersion measurements. Global fitting of the corresponding data yielded kinetic rate constants of the underlying equilibrium and populations and lifetimes of solvent-exposed states. The latter were influenced by acyl chain composition and ranged from milliseconds to submilliseconds for chains containing six, eight, and ten carbons, owing to their variable interactions with AcpP's hydrophobic core. Although transient, the exposure of AcpP-tethered acyl chains to the solvent may allow relevant enzymes to gain access to its active thioester, and the enzyme-induced selection of this conformation will culminate in the production of fatty acids.
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Affiliation(s)
- Brianna N. Kalaj
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - James J. La Clair
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Charles D. Schwieters
- Computational Biomolecular Magnetic Resonance Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lalit Deshmukh
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
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5
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Schanda P, Haran G. NMR and Single-Molecule FRET Insights into Fast Protein Motions and Their Relation to Function. Annu Rev Biophys 2024; 53:247-273. [PMID: 38346243 DOI: 10.1146/annurev-biophys-070323-022428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/18/2024]
Abstract
Proteins often undergo large-scale conformational transitions, in which secondary and tertiary structure elements (loops, helices, and domains) change their structures or their positions with respect to each other. Simple considerations suggest that such dynamics should be relatively fast, but the functional cycles of many proteins are often relatively slow. Sophisticated experimental methods are starting to tackle this dichotomy and shed light on the contribution of large-scale conformational dynamics to protein function. In this review, we focus on the contribution of single-molecule Förster resonance energy transfer and nuclear magnetic resonance (NMR) spectroscopies to the study of conformational dynamics. We briefly describe the state of the art in each of these techniques and then point out their similarities and differences, as well as the relative strengths and weaknesses of each. Several case studies, in which the connection between fast conformational dynamics and slower function has been demonstrated, are then introduced and discussed. These examples include both enzymes and large protein machines, some of which have been studied by both NMR and fluorescence spectroscopies.
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Affiliation(s)
- Paul Schanda
- Institute of Science and Technology Austria (ISTA), Klosterneuburg, Austria;
| | - Gilad Haran
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel;
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6
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Toyama Y, Shimada I. Quantitative analysis of the slow exchange process by 19F NMR in the presence of scalar and dipolar couplings: applications to the ribose 2'- 19F probe in nucleic acids. JOURNAL OF BIOMOLECULAR NMR 2024:10.1007/s10858-024-00446-7. [PMID: 38918317 DOI: 10.1007/s10858-024-00446-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Accepted: 06/10/2024] [Indexed: 06/27/2024]
Abstract
Solution NMR spectroscopy is a particularly powerful technique for characterizing the functional dynamics of biomolecules, which is typically achieved through the quantitative characterization of chemical exchange processes via the measurement of spin relaxation rates. In addition to the conventional nuclei such as 15N and 13C, which are abundant in biomolecules, fluorine-19 (19F) has recently garnered attention and is being widely used as a site-specific spin probe. While 19F offers the advantages of high sensitivity and low background, it can be susceptible to artifacts in quantitative relaxation analyses due to a multitude of dipolar and scalar coupling interactions with nearby 1H spins. In this study, we focused on the ribose 2'-19F spin probe in nucleic acids and investigated the effects of 1H-19F spin interactions on the quantitative characterization of slow exchange processes on the millisecond time scale. We demonstrated that the 1H-19F dipolar coupling can significantly affect the interpretation of 19F chemical exchange saturation transfer (CEST) experiments when 1H decoupling is applied, while the 1H-19F interactions have a lesser impact on Carr-Purcell-Meiboom-Gill relaxation dispersion applications. We also proposed a modified CEST scheme to alleviate these artifacts along with experimental verifications on self-complementary RNA systems. The theoretical framework presented in this study can be widely applied to various 19F spin systems where 1H-19F interactions are operative, further expanding the utility of 19F relaxation-based NMR experiments.
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Affiliation(s)
- Yuki Toyama
- Laboratory for Dynamic Structure of Biomolecules, RIKEN Center for Biosystems Dynamics Research (BDR), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
| | - Ichio Shimada
- Laboratory for Dynamic Structure of Biomolecules, RIKEN Center for Biosystems Dynamics Research (BDR), 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
- Graduate School of Integrated Sciences for Life, Hiroshima University, 1-4-4, Kagamiyama, Higashi-Hiroshima, 739-8528, Japan.
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7
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Wayment-Steele HK, Otten R, Pitsawong W, Ojoawo AM, Glaser A, Calderone LA, Kern D. The conformational landscape of fold-switcher KaiB is tuned to the circadian rhythm timescale. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.03.597139. [PMID: 38895306 PMCID: PMC11185700 DOI: 10.1101/2024.06.03.597139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
How can a single protein domain encode a conformational landscape with multiple stably-folded states, and how do those states interconvert? Here, we use real-time and relaxation-dispersion NMR to characterize the conformational landscape of the circadian rhythm protein KaiB from Rhodobacter sphaeroides. Unique among known natural metamorphic proteins, this KaiB variant spontaneously interconverts between two monomeric states: the "Ground" and "Fold-switched" (FS) state. KaiB in its FS state interacts with multiple binding partners, including the central KaiC protein, to regulate circadian rhythms. We find that KaiB itself takes hours to interconvert between the Ground and FS state, underscoring the ability of a single sequence to encode the slow process needed for function. We reveal the rate-limiting step between the Ground and FS state is the cis-trans isomerization of three prolines in the fold-switching region by demonstrating interconversion acceleration by the prolyl isomerase CypA. The interconversion proceeds through a "partially disordered" (PD) state, where the C-terminal half becomes disordered while the N-terminal half remains stably folded. We discovered two additional properties of KaiB's landscape. Firstly, the Ground state experiences cold denaturation: at 4°C, the PD state becomes the majorly populated state. Secondly, the Ground state exchanges with a fourth state, the "Enigma" state, on the millisecond timescale. We combine AlphaFold2-based predictions and NMR chemical shift predictions to predict this "Enigma" state is a beta-strand register shift that eases buried charged residues, and support this structure experimentally. These results provide mechanistic insight in how evolution can design a single sequence that achieves specific timing needed for its function.
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Affiliation(s)
- Hannah K Wayment-Steele
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
| | - Renee Otten
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
- Present address: Treeline Biosciences, Watertown, MA, USA
| | - Warintra Pitsawong
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
- Present address: Biomolecular Discovery, Relay Therapeutics, Cambridge, MA, USA
| | - Adedolapo M Ojoawo
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
| | - Andrew Glaser
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
| | - Logan A Calderone
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
| | - Dorothee Kern
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Waltham, MA, USA
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8
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Gampp O, Kadavath H, Riek R. NMR tools to detect protein allostery. Curr Opin Struct Biol 2024; 86:102792. [PMID: 38428364 DOI: 10.1016/j.sbi.2024.102792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/06/2024] [Accepted: 02/14/2024] [Indexed: 03/03/2024]
Abstract
Allostery is a fundamental mechanism of cellular homeostasis by intra-protein communication between distinct functional sites. It is an internal process of proteins to steer interactions not only with each other but also with other biomolecules such as ligands, lipids, and nucleic acids. In addition, allosteric regulation is particularly important in enzymatic activities. A major challenge in structural and molecular biology today is unraveling allosteric sites in proteins, to elucidate the detailed mechanism of allostery and the development of allosteric drugs. Here we summarize the recently developed tools and approaches which enable the elucidation of regulatory hotspots and correlated motion in biomolecules, focusing primarily on solution-state nuclear magnetic resonance spectroscopy (NMR). These tools open an avenue towards a rational understanding of the mechanism of allostery and provide essential information for the design of allosteric drugs.
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Affiliation(s)
- Olivia Gampp
- Laboratory of Physical Chemistry, ETH Zurich, Switzerland
| | - Harindranath Kadavath
- Laboratory of Physical Chemistry, ETH Zurich, Switzerland; St. Jude Children's Research Hospital, 262 Danny Thomas Place, 38105 Memphis, Tennessee, USA. https://twitter.com/harijik
| | - Roland Riek
- Laboratory of Physical Chemistry, ETH Zurich, Switzerland.
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9
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Khandave NP, Hansen DF, Vallurupalli P. Increasing the accuracy of exchange parameters reporting on slow dynamics by performing CEST experiments with 'high' B 1 fields. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 363:107699. [PMID: 38851059 DOI: 10.1016/j.jmr.2024.107699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/03/2024] [Revised: 05/11/2024] [Accepted: 05/11/2024] [Indexed: 06/10/2024]
Abstract
Over the last decade chemical exchange saturation transfer (CEST) NMR methods have emerged as powerful tools to characterize biomolecular conformational dynamics occurring between a visible major state and 'invisible' minor states. The ability of the CEST experiment to detect these minor states, and provide precise exchange parameters, hinges on using appropriate B1 field strengths during the saturation period. Typically, a pair of B1 fields with ω1 (=2πB1) values around the exchange rate kex are chosen. Here we show that the transverse relaxation rate of the minor state resonance (R2,B) also plays a crucial role in determining the B1 fields that lead to the most informative datasets. Using [Formula: see text] ≥ kex, to guide the choice of B1, instead of kex, leads to data wherefrom substantially more accurate exchange parameters can be derived. The need for higher B1 fields, guided by K, is demonstrated by studying the conformational exchange in two mutants of the 71 residue FF domain with kex ∼ 11 s-1 and ∼ 72 s-1, respectively. In both cases analysis of CEST datasets recorded using B1 field values guided by kex lead to imprecise exchange parameters, whereas using B1 values guided by K resulted in precise site-specific exchange parameters. The conclusions presented here will be valuable while using CEST to study slow processes at sites with large intrinsic relaxation rates, including carbonyl sites in small to medium sized proteins, amide 15N sites in large proteins and when the minor state dips are broadened due to exchange among the minor states.
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Affiliation(s)
- Nihar Pradeep Khandave
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500046, India
| | - D Flemming Hansen
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, United Kingdom; The Francis Crick Institute, London, NW1 1BF, United Kingdom.
| | - Pramodh Vallurupalli
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500046, India.
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10
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Neelam, Singh H. 1H, 15N and 13C resonance assignments of S2A mutant of human carbonic anhydrase II. BIOMOLECULAR NMR ASSIGNMENTS 2024; 18:45-49. [PMID: 38520652 DOI: 10.1007/s12104-024-10166-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Accepted: 02/22/2024] [Indexed: 03/25/2024]
Abstract
In preparation for a detailed exploration of the structural and functional aspects of the Ser2Ala mutant of human carbonic anhydrase II, we present here almost complete sequence-specific resonance assignments for 1H, 15N, and 13C. The mutation of serine to alanine at position 2, located in the N-terminal region of the enzyme, significantly alters the hydrophilic nature of the site, rendering it hydrophobic. Consequently, there is an underlying assumption that this mutation would repel water from the site. However, intriguingly, comparative analysis of the mutant structure with the wild type reveals minimal discernible differences. These assignments serve as the basis for in-depth studies on histidine dynamics, protonation states, and its intricate role in protein-water interactions and catalysis.
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Affiliation(s)
- Neelam
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, Berhampur, Odisha, 760010, India
| | - Himanshu Singh
- Department of Chemical Sciences, Indian Institute of Science Education and Research Berhampur, Berhampur, Odisha, 760010, India.
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11
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Manghrani A, Rangadurai AK, Szekely O, Liu B, Guseva S, Al-Hashimi HM. Quantitative and systematic NMR measurements of sequence-dependent A-T Hoogsteen dynamics uncovers unique conformational specificity in the DNA double helix. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.15.594415. [PMID: 38798635 PMCID: PMC11118333 DOI: 10.1101/2024.05.15.594415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2024]
Abstract
The propensities to form lowly-populated short-lived conformations of DNA could vary with sequence, providing an important source of sequence-specificity in biochemical reactions. However, comprehensively measuring how these dynamics vary with sequence is challenging. Using 1H CEST and 13C R 1 ρ NMR, we measured Watson-Crick to Hoogsteen dynamics for an A-T base pair in thirteen trinucleotide sequence contexts. The Hoogsteen population and exchange rate varied 4-fold and 16-fold, respectively, and were dependent on both the 3'- and 5'-neighbors but only weakly dependent on monovalent ion concentration (25 versus 100 mM NaCl) and pH (6.8 versus 8.0). Flexible TA and CA dinucleotide steps exhibited the highest Hoogsteen populations, and their kinetics rates strongly depended on the 3'-neighbor. In contrast, the stiffer AA and GA steps had the lowest Hoogsteen population, and their kinetics were weakly dependent on the 3'-neighbor. The Hoogsteen lifetime was especially short when G-C neighbors flanked the A-T base pair. The Hoogsteen dynamics had a distinct sequence-dependence compared to duplex stability and minor groove width. Thus, our results uncover a unique source of sequence-specificity hidden within the DNA double helix in the form of A-T Hoogsteen dynamics and establish the utility of 1H CEST to quantitively measure sequence-dependent DNA dynamics.
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Affiliation(s)
- Akanksha Manghrani
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27705, United States
| | - Atul Kaushik Rangadurai
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27705, United States
- Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada
| | - Or Szekely
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27705, United States
| | - Bei Liu
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27705, United States
| | - Serafima Guseva
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, United States
| | - Hashim M. Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, United States
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12
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Gu S, Al-Hashimi HM. Direct Measurement of 8OG Syn-Anti Flips in Mutagenic 8OG·A and Long-Range Damage-Dependent Hoogsteen Breathing Dynamics Using 1H CEST NMR. J Phys Chem B 2024; 128:4087-4096. [PMID: 38644782 DOI: 10.1021/acs.jpcb.4c00316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/23/2024]
Abstract
Elucidating how damage impacts DNA dynamics is essential for understanding the mechanisms of damage recognition and repair. Many DNA lesions alter their propensities to form low-populated and short-lived conformational states. However, NMR methods to measure these dynamics require isotopic enrichment, which is difficult for damaged nucleotides. Here, we demonstrate the utility of the 1H chemical exchange saturation transfer (CEST) NMR experiment in measuring the dynamics of oxidatively damaged 8-oxoguanine (8OG) in the mutagenic 8OGsyn·Aanti mismatch. Using 8OG-H7 as an NMR probe of the damaged base, we directly measured 8OG syn-anti flips to form a lowly populated (pop. ∼ 5%) and short-lived (lifetime ∼50 ms) nonmutagenic 8OGanti·Aanti. These exchange parameters were in quantitative agreement with values from 13C off-resonance R1ρ and CEST on the labeled partner adenine. The Watson-Crick-like 8OGsyn·Aanti mismatch also rescued the kinetics of Hoogsteen motions at distant A-T base pairs, which the G·A mismatch had slowed down. The results lend further support for 8OGanti·Aanti as a minor conformational state of 8OG·A, reveal that 8OG damage can impact Hoogsteen dynamics at a distance, and demonstrate the utility of 1H CEST for measuring damage-dependent dynamics in unlabeled DNA.
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Affiliation(s)
- Stephanie Gu
- Department of Biochemistry, Duke University School of Medicine, Durham, North Carolina 27710, United States
| | - Hashim M Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, New York 10032, United States
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13
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Zoltsman G, Dang TL, Kuchersky M, Faust O, Silva MS, Ilani T, Wentink AS, Bukau B, Rosenzweig R. A unique chaperoning mechanism in class A JDPs recognizes and stabilizes mutant p53. Mol Cell 2024; 84:1512-1526.e9. [PMID: 38508184 DOI: 10.1016/j.molcel.2024.02.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 12/14/2023] [Accepted: 02/20/2024] [Indexed: 03/22/2024]
Abstract
J-domain proteins (JDPs) constitute a large family of molecular chaperones that bind a broad spectrum of substrates, targeting them to Hsp70, thus determining the specificity of and activating the entire chaperone functional cycle. The malfunction of JDPs is therefore inextricably linked to myriad human disorders. Here, we uncover a unique mechanism by which chaperones recognize misfolded clients, present in human class A JDPs. Through a newly identified β-hairpin site, these chaperones detect changes in protein dynamics at the initial stages of misfolding, prior to exposure of hydrophobic regions or large structural rearrangements. The JDPs then sequester misfolding-prone proteins into large oligomeric assemblies, protecting them from aggregation. Through this mechanism, class A JDPs bind destabilized p53 mutants, preventing clearance of these oncoproteins by Hsp70-mediated degradation, thus promoting cancer progression. Removal of the β-hairpin abrogates this protective activity while minimally affecting other chaperoning functions. This suggests the class A JDP β-hairpin as a highly specific target for cancer therapeutics.
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Affiliation(s)
- Guy Zoltsman
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel
| | - Thi Lieu Dang
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH-Alliance, Im Neuenheimer Feld 282, Heidelberg 69120, Germany
| | - Miriam Kuchersky
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel
| | - Ofrah Faust
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel
| | - Micael S Silva
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel
| | - Tal Ilani
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel
| | - Anne S Wentink
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH-Alliance, Im Neuenheimer Feld 282, Heidelberg 69120, Germany; Leiden Institute of Chemistry, Leiden University, Einsteinweg 55, 2333CC Leiden, the Netherlands
| | - Bernd Bukau
- Center for Molecular Biology of Heidelberg University (ZMBH) and German Cancer Research Center (DKFZ), DKFZ-ZMBH-Alliance, Im Neuenheimer Feld 282, Heidelberg 69120, Germany.
| | - Rina Rosenzweig
- Department of Chemical and Structural Biology, Weizmann Institute of Science, Rehovot 761000, Israel.
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14
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Cui Y, Jin Y, Hou Y, Han X, Cao H, Kay LE, Yuwen T. Optimization of TROSY- and anti-TROSY-based 15N CPMG relaxation dispersion experiments through phase cycling. JOURNAL OF MAGNETIC RESONANCE (SAN DIEGO, CALIF. : 1997) 2024; 361:107629. [PMID: 38503148 DOI: 10.1016/j.jmr.2024.107629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 01/26/2024] [Accepted: 01/27/2024] [Indexed: 03/21/2024]
Abstract
CPMG relaxation dispersion studies of biomolecular dynamics on the μs-ms timescale can provide detailed kinetic, thermodynamic, and structural insights into function. Frequently, the 15N spin serves as the probe of choice, as uniform incorporation of the 15N isotope is facile and cost-effective, and the interpretation of the resulting data is often relatively straightforward. In conventional CPMG relaxation dispersion experiments the application of CPMG pulses with constant radiofrequency (RF) phase can lead to artifactual dispersion profiles that result from off-resonance effects, RF field inhomogeneity, and pulse miscalibration. The development of CPMG experiments with the [0013]-phase cycle has significantly reduced the impact of pulse imperfections over a greater bandwidth of frequency offsets in comparison to constant phase experiments. Application of 15N-TROSY-based CPMG schemes to studies of the dynamics of large molecules is necessary for high sensitivity, yet the correct incorporation of the [0013]-phase cycle is non-trivial. Here we present TROSY- and anti-TROSY-based 15N CPMG experiments with the [0013]-phase cycling scheme and demonstrate, through comprehensive numerical simulations and experimental validation, enhanced resistance to pulse imperfections relative to traditional schemes utilizing constant phase CPMG pulses. Notably, exchange parameters derived from the new experiments are in good agreement with those obtained using other, more established, 15N-based CPMG approaches.
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Affiliation(s)
- Yingxian Cui
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yangzhuoyue Jin
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Yu Hou
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Xiaoxu Han
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Haiyan Cao
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6, Canada; Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, Ontario M5G 1X8, Canada.
| | - Tairan Yuwen
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Pharmaceutical Analysis, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
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15
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Maiti S, Singh A, Maji T, Saibo NV, De S. Experimental methods to study the structure and dynamics of intrinsically disordered regions in proteins. Curr Res Struct Biol 2024; 7:100138. [PMID: 38707546 PMCID: PMC11068507 DOI: 10.1016/j.crstbi.2024.100138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 03/12/2024] [Accepted: 03/15/2024] [Indexed: 05/07/2024] Open
Abstract
Eukaryotic proteins often feature long stretches of amino acids that lack a well-defined three-dimensional structure and are referred to as intrinsically disordered proteins (IDPs) or regions (IDRs). Although these proteins challenge conventional structure-function paradigms, they play vital roles in cellular processes. Recent progress in experimental techniques, such as NMR spectroscopy, single molecule FRET, high speed AFM and SAXS, have provided valuable insights into the biophysical basis of IDP function. This review discusses the advancements made in these techniques particularly for the study of disordered regions in proteins. In NMR spectroscopy new strategies such as 13C detection, non-uniform sampling, segmental isotope labeling, and rapid data acquisition methods address the challenges posed by spectral overcrowding and low stability of IDPs. The importance of various NMR parameters, including chemical shifts, hydrogen exchange rates, and relaxation measurements, to reveal transient secondary structures within IDRs and IDPs are presented. Given the high flexibility of IDPs, the review outlines NMR methods for assessing their dynamics at both fast (ps-ns) and slow (μs-ms) timescales. IDPs exert their functions through interactions with other molecules such as proteins, DNA, or RNA. NMR-based titration experiments yield insights into the thermodynamics and kinetics of these interactions. Detailed study of IDPs requires multiple experimental techniques, and thus, several methods are described for studying disordered proteins, highlighting their respective advantages and limitations. The potential for integrating these complementary techniques, each offering unique perspectives, is explored to achieve a comprehensive understanding of IDPs.
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Affiliation(s)
| | - Aakanksha Singh
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, WB, 721302, India
| | - Tanisha Maji
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, WB, 721302, India
| | - Nikita V. Saibo
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, WB, 721302, India
| | - Soumya De
- School of Bioscience, Indian Institute of Technology Kharagpur, Kharagpur, WB, 721302, India
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16
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Tiwari VP, De D, Thapliyal N, Kay LE, Vallurupalli P. Beyond slow two-state protein conformational exchange using CEST: applications to three-state protein interconversion on the millisecond timescale. JOURNAL OF BIOMOLECULAR NMR 2024; 78:39-60. [PMID: 38169015 DOI: 10.1007/s10858-023-00431-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 11/15/2023] [Indexed: 01/05/2024]
Abstract
Although NMR spectroscopy is routinely used to study the conformational dynamics of biomolecules, robust analyses of the data are challenged in cases where exchange is more complex than two-state, such as when a 'visible' major conformer exchanges with two 'invisible' minor states on the millisecond timescale. It is becoming increasingly clear that chemical exchange saturation transfer (CEST) NMR experiments that were initially developed to study systems undergoing slow interconversion are also sensitive to intermediate-fast timescale biomolecular conformational exchange. Here we investigate the utility of the amide 15N CEST experiment to characterise protein three-state exchange occurring on the millisecond timescale by studying the interconversion between the folded (F) state of the FF domain from human HYPA/FBP11 (WT FF) and two of its folding intermediates I1 and I2. Although 15N CPMG experiments are consistent with the F state interconverting with a single minor state on the millisecond timescale, 15N CEST data clearly establish an exchange process between F and a pair of minor states. A unique three-state exchange model cannot be obtained by analysis of 15N CEST data recorded at a single temperature. However, including the relative sign of the difference in the chemical shifts of the two minor states based on a simple two-state analysis of CEST data recorded at multiple temperatures, results in a robust three-state model in which the F, I1 and I2 states interconvert with each other on the millisecond timescale ( k e x , F I 1 ~ 550 s-1, k e x , F I 2 ~ 1200 s-1, k e x , I 1 I 2 ~ 5000 s-1), with I1 and I2 sparsely populated at ~ 0.15% and ~ 0.35%, respectively, at 15 °C. A computationally demanding grid-search of exchange parameter space is not required to extract the best-fit exchange parameters from the CEST data. The utility of the CEST experiment, thus, extends well beyond studies of conformers in slow exchange on the NMR chemical shift timescale, to include systems with interconversion rates on the order of thousands/second.
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Affiliation(s)
- Ved Prakash Tiwari
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500046, India
| | - Debajyoti De
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500046, India
| | - Nemika Thapliyal
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500046, India
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, M5S 1A8, Canada.
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
| | - Pramodh Vallurupalli
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500046, India.
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17
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Gelenter MD, Yau WM, Anfinrud PA, Bax A. From Milliseconds to Minutes: Melittin Self-Assembly from Concerted Non-Equilibrium Pressure-Jump and Equilibrium Relaxation Nuclear Magnetic Resonance. J Phys Chem Lett 2024; 15:1930-1935. [PMID: 38346015 PMCID: PMC10896212 DOI: 10.1021/acs.jpclett.3c03563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/25/2024] [Accepted: 01/29/2024] [Indexed: 02/23/2024]
Abstract
Non-equilibrium kinetics techniques like pressure-jump nuclear magnetic resonance (NMR) are powerful in tracking changes in oligomeric populations and are not limited by relaxation rates for the time scales of exchange that can be probed. However, these techniques are less sensitive to minor, transient populations than are Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments. We integrated non-equilibrium pressure-jump and equilibrium CPMG relaxation dispersion data to fully map the kinetic landscape of melittin tetramerization. While monomeric peptides weakly form dimers (Kd,D/M ≈ 26 mM) whose population never exceeds 1.6% at 288 K, dimers associate tightly to form stable tetrameric species (Kd,T/D ≈ 740 nM). Exchange between the monomer and dimer, along with exchange between the dimer and tetramer, occurs on the millisecond time scale. The NMR approach developed herein can be readily applied to studying the folding and misfolding of a wide range of oligomeric assemblies.
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Affiliation(s)
- Martin D Gelenter
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 Memorial Drive, Bethesda, Maryland 20892, United States
| | - Wai-Ming Yau
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 Memorial Drive, Bethesda, Maryland 20892, United States
| | - Philip A Anfinrud
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 Memorial Drive, Bethesda, Maryland 20892, United States
| | - Ad Bax
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, 5 Memorial Drive, Bethesda, Maryland 20892, United States
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18
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Karamanos TK, Matthews S. Biomolecular NMR in the AI-assisted structural biology era: Old tricks and new opportunities. BIOCHIMICA ET BIOPHYSICA ACTA. PROTEINS AND PROTEOMICS 2024; 1872:140949. [PMID: 37572958 DOI: 10.1016/j.bbapap.2023.140949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 08/07/2023] [Accepted: 08/09/2023] [Indexed: 08/14/2023]
Abstract
Over the last 40 years nuclear magnetic resonance (NMR) spectroscopy has established itself as one of the most versatile techniques for the characterization of biomolecules, especially proteins. Given the molecular size limitations of NMR together with recent advances in cryo-electron microscopy and artificial intelligence-assisted protein structure prediction, the bright future of NMR in structural biology has been put into question. In this mini review we argue the contrary. We discuss the unique opportunities solution NMR offers to the protein chemist that distinguish it from all other experimental or computational methods, and how it can benefit from machine learning.
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Affiliation(s)
| | - Stephen Matthews
- Department of Life Sciences, Faculty of Natural Sciences, Imperial College London.
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19
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Lu J, Straub JS, Nowotarski MS, Han S, Xu X, Jerschow A. Spectroscopically dark phosphate features revealed by chemical exchange saturation transfer. NMR IN BIOMEDICINE 2024; 37:e5057. [PMID: 37853675 DOI: 10.1002/nbm.5057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Revised: 08/16/2023] [Accepted: 09/13/2023] [Indexed: 10/20/2023]
Abstract
Phosphate is an essential anion in the human body, comprising approximately 1% of the total body weight, and playing a vital role in metabolism, cell membranes, and bone formation. We have recently provided spectroscopic, microscopic, and computational evidence indicating that phosphates can aggregate much more readily in solution than previously thought. This prior work provided indirect evidence through the observation of unusual31 P NMR relaxation and line-broadening effects with increasing temperature. Here, we show that, under conditions of slow exchange and selective RF saturation, additional features become visible in chemical exchange saturation transfer (CEST) experiments, which appear to be related to the previously reported phosphate clustering. In particular, CEST shows pronounced dips several ppm upfield of the main phosphate resonance at low temperatures, while direct31 P spectroscopy does not produce any signals in that range. We study the pH dependence of these new spectroscopic features and present exchange and spectroscopic parameters based on fitting the CEST data. These findings could be of importance in the investigation of phosphate dynamics, especially in the biological milieu.
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Affiliation(s)
- Jiaqi Lu
- Department of Chemistry, New York University, New York, USA
| | - Joshua S Straub
- Department of Physics, University of California, Santa Barbara, California, USA
| | | | - Songi Han
- Department of Chemistry, University of California, Santa Barbara, California, USA
- Department of Chemical Engineering, University of California, Santa Barbara, California, USA
| | - Xiang Xu
- BioMedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, USA
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20
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Theisen FF, Prestel A, Elkjær S, Leurs YHA, Morffy N, Strader LC, O'Shea C, Teilum K, Kragelund BB, Skriver K. Molecular switching in transcription through splicing and proline-isomerization regulates stress responses in plants. Nat Commun 2024; 15:592. [PMID: 38238333 PMCID: PMC10796322 DOI: 10.1038/s41467-024-44859-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 01/09/2024] [Indexed: 01/22/2024] Open
Abstract
The Arabidopsis thaliana DREB2A transcription factor interacts with the negative regulator RCD1 and the ACID domain of subunit 25 of the transcriptional co-regulator mediator (Med25) to integrate stress signals for gene expression, with elusive molecular interplay. Using biophysical and structural analyses together with high-throughput screening, we reveal a bivalent binding switch in DREB2A containing an ACID-binding motif (ABS) and the known RCD1-binding motif (RIM). The RIM is lacking in a stress-induced DREB2A splice variant with retained transcriptional activity. ABS and RIM bind to separate sites on Med25-ACID, and NMR analyses show a structurally heterogeneous complex deriving from a DREB2A-ABS proline residue populating cis- and trans-isomers with remote impact on the RIM. The cis-isomer stabilizes an α-helix, while the trans-isomer may introduce energetic frustration facilitating rapid exchange between activators and repressors. Thus, DREB2A uses a post-transcriptionally and post-translationally modulated switch for transcriptional regulation.
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Affiliation(s)
- Frederik Friis Theisen
- The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Andreas Prestel
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Steffie Elkjær
- The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Yannick H A Leurs
- The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | | | - Charlotte O'Shea
- The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Kaare Teilum
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
| | - Karen Skriver
- The REPIN and The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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21
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Gu S, Al-Hashimi HM. Direct Measurement of 8OG syn-anti Flips in Mutagenic 8OG•A and Long-Range Damage-Dependent Hoogsteen Breathing Dynamics Using 1H CEST NMR. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.15.575532. [PMID: 38293035 PMCID: PMC10827055 DOI: 10.1101/2024.01.15.575532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Elucidating how damage impacts DNA dynamics is essential for understanding the mechanisms of damage recognition and repair. Many DNA lesions alter the propensities to form lowly-populated and short-lived conformational states. However, NMR methods to measure these dynamics require isotopic enrichment, which is difficult for damaged nucleotides. Here, we demonstrate the utility of the 1H chemical exchange saturation transfer (CEST) NMR experiment in measuring the dynamics of oxidatively damaged 8-oxoguanine (8OG) in the mutagenic 8OGsyn•Aanti mismatch. Using 8OG-H7 as an NMR probe of the damaged base, we directly measured 8OG syn-anti flips to form a lowly-populated (pop. ~ 5%) and short-lived (lifetime ~ 50 ms) non-mutagenic 8OGanti•Aanti. These exchange parameters were in quantitative agreement with values from 13C off-resonance R1ρ and CEST on a labeled partner adenine. The Watson-Crick-like 8OGsyn•Aanti mismatch also rescued the kinetics of Hoogsteen motions at distance A-T base pairs, which the G•A mismatch had slowed down. The results lend further support for 8OGanti•Aanti as a minor conformational state of 8OG•A, reveal that 8OG damage can impact Hoogsteen dynamics at a distance, and demonstrate the utility of 1H CEST for measuring damage-dependent dynamics in unlabeled DNA.
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Affiliation(s)
- Stephanie Gu
- Department of Biochemistry, Duke University School of Medicine, Durham, NC, USA
| | - Hashim M. Al-Hashimi
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, USA
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22
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Jain S, Sekhar A. Transient excited states of the metamorphic protein Mad2 and their implications for function. Proteins 2024. [PMID: 38221646 DOI: 10.1002/prot.26667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Revised: 12/27/2023] [Accepted: 01/01/2024] [Indexed: 01/16/2024]
Abstract
The spindle checkpoint complex is a key surveillance mechanism in cell division that prevents premature separation of sister chromatids. Mad2 is an integral component of this spindle checkpoint complex that recognizes cognate substrates such as Mad1 and Cdc20 in its closed (C-Mad2) conformation by fastening a "seatbelt" around short peptide regions that bind to the substrate recognition site. Mad2 is also a metamorphic protein that adopts not only the fold found in C-Mad2, but also a structurally distinct open conformation (O-Mad2) which is incapable of binding substrates. Here, we show using chemical exchange saturation transfer (CEST) and relaxation dispersion (CPMG) NMR experiments that Mad2 transiently populates three other higher free energy states with millisecond lifetimes, two in equilibrium with C-Mad2 (E1 and E2) and one with O-Mad2 (E3). E1 is a mimic of substrate-bound C-Mad2 in which the N-terminus of one C-Mad2 molecule inserts into the seatbelt region of a second molecule of C-Mad2, providing a potential pathway for autoinhibition of C-Mad2. E2 is the "unbuckled" conformation of C-Mad2 that facilitates the triage of molecules along competing fold-switching and substrate binding pathways. The E3 conformation that coexists with O-Mad2 shows fluctuations at a hydrophobic lock that is required for stabilizing the O-Mad2 fold and we hypothesize that E3 represents an early intermediate on-pathway towards conversion to C-Mad2. Collectively, the NMR data highlight the rugged free energy landscape of Mad2 with multiple low-lying intermediates that interlink substrate-binding and fold-switching, and also emphasize the role of molecular dynamics in its function.
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Affiliation(s)
- Shefali Jain
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, Karnataka, India
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23
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Zinke M, Lejeune M, Mechaly A, Bardiaux B, Boneca IG, Delepelaire P, Izadi-Pruneyre N. Ton motor conformational switch and peptidoglycan role in bacterial nutrient uptake. Nat Commun 2024; 15:331. [PMID: 38184686 PMCID: PMC10771500 DOI: 10.1038/s41467-023-44606-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 12/20/2023] [Indexed: 01/08/2024] Open
Abstract
Active nutrient uptake is fundamental for survival and pathogenicity of Gram-negative bacteria, which operate a multi-protein Ton system to transport essential nutrients like metals and vitamins. This system harnesses the proton motive force at the inner membrane to energize the import through the outer membrane, but the mechanism of energy transfer remains enigmatic. Here, we study the periplasmic domain of ExbD, a crucial component of the proton channel of the Ton system. We show that this domain is a dynamic dimer switching between two conformations representing the proton channel's open and closed states. By in vivo phenotypic assays we demonstrate that this conformational switch is essential for the nutrient uptake by bacteria. The open state of ExbD triggers a disorder to order transition of TonB, enabling TonB to supply energy to the nutrient transporter. We also reveal the anchoring role of the peptidoglycan layer in this mechanism. Herein, we propose a mechanistic model for the Ton system, emphasizing ExbD duality and the pivotal catalytic role of peptidoglycan. Sequence analysis suggests that this mechanism is conserved in other systems energizing gliding motility and membrane integrity. Our study fills important gaps in understanding bacterial motor mechanism and proposes novel antibacterial strategies.
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Affiliation(s)
- Maximilian Zinke
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France
| | - Maylis Lejeune
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France
| | - Ariel Mechaly
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Crystallography Platform, F-75015, Paris, France
| | - Benjamin Bardiaux
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France
| | - Ivo Gomperts Boneca
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité de Biologie et génétique de la paroi bactérienne, F-75015, Paris, France
| | - Philippe Delepelaire
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université Paris Cité, UMR7099 CNRS, F-75005, Paris, France
- Institut de Biologie Physico-Chimique, F-75005, Paris, France
| | - Nadia Izadi-Pruneyre
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015, Paris, France.
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24
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Pavlović RZ, Finnegan TJ, Metlushko A, Hansen AL, Waudby CA, Wang X, Hoefer N, McComb DW, Pavić A, Plackić N, Novaković J, Bradić J, Jeremić N, Jakovljević V, Šmit B, Matić S, Alvarez-Saavedra MA, Čapo I, Moore CE, Stupp SI, Badjić JD. Dynamic and Assembly Characteristics of Deep-Cavity Basket Acting as a Host for Inclusion Complexation of Mitoxantrone in Biotic and Abiotic Systems. Chemistry 2023; 29:e202303374. [PMID: 37851342 DOI: 10.1002/chem.202303374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 10/16/2023] [Accepted: 10/18/2023] [Indexed: 10/19/2023]
Abstract
We describe the preparation, dynamic, assembly characteristics of vase-shaped basket 13- along with its ability to form an inclusion complex with anticancer drug mitoxantrone in abiotic and biotic systems. This novel cavitand has a deep nonpolar pocket consisting of three naphthalimide sides fused to a bicyclic platform at the bottom while carrying polar glycines at the top. The results of 1 H Nuclear Magnetic Resonance (NMR), 1 H NMR Chemical Exchange Saturation Transfer (CEST), Calorimetry, Hybrid Replica Exchange Molecular Dynamics (REMD), and Microcrystal Electron Diffraction (MicroED) measurements are in line with 1 forming dimer [12 ]6- , to be in equilibrium with monomers 1(R) 3- (relaxed) and 1(S) 3- (squeezed). Through simultaneous line-shape analysis of 1 H NMR data, kinetic and thermodynamic parameters characterizing these equilibria were quantified. Basket 1(R) 3- includes anticancer drug mitoxantrone (MTO2+ ) in its pocket to give stable binary complex [MTO⊂1]- (Kd =2.1 μM) that can be precipitated in vitro with UV light or pH as stimuli. Both in vitro and in vivo studies showed that the basket is nontoxic, while at a higher proportion with respect to MTO it reduced its cytotoxicity in vitro. With well-characterized internal dynamics and dimerization, the ability to include mitoxantrone, and biocompatibility, the stage is set to develop sequestering agents from deep-cavity baskets.
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Affiliation(s)
- Radoslav Z Pavlović
- Department of Chemistry & Biochemistry, The Ohio State University, 1100 W. 18th Avenue, Columbus, OH, 43210, USA
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, USA
- Department of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Department of Materials Science and Engineering, Northwestern University, Chicago, IL, 60208, USA
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, 60208, USA)
| | - Tyler J Finnegan
- Department of Chemistry & Biochemistry, The Ohio State University, 1100 W. 18th Avenue, Columbus, OH, 43210, USA
| | - Anna Metlushko
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, USA
- Department of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Department of Materials Science and Engineering, Northwestern University, Chicago, IL, 60208, USA
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, 60208, USA)
| | - Alexandar L Hansen
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, 43210, USA
| | | | - Xiuze Wang
- Department of Chemistry & Biochemistry, The Ohio State University, 1100 W. 18th Avenue, Columbus, OH, 43210, USA
| | - Nicole Hoefer
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, OH, 43210, USA
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - David W McComb
- Center for Electron Microscopy and Analysis, The Ohio State University, Columbus, OH, 43210, USA
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, 43210, USA
| | - Aleksandar Pavić
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11000, Belgrade, Serbia
| | - Nikola Plackić
- Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, 11000, Belgrade, Serbia
| | - Jovana Novaković
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
- Center for Excellence for Redox Balance Research in Cardiovascular and Metabolic Disorders, Kragujevac, Serbia
| | - Jovana Bradić
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
- Center for Excellence for Redox Balance Research in Cardiovascular and Metabolic Disorders, Kragujevac, Serbia
| | - Nevena Jeremić
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
- Center for Excellence for Redox Balance Research in Cardiovascular and Metabolic Disorders, Kragujevac, Serbia
| | - Vladimir Jakovljević
- Department of Pharmacy, Faculty of Medical Sciences, University of Kragujevac, Kragujevac, Serbia
- Center for Excellence for Redox Balance Research in Cardiovascular and Metabolic Disorders, Kragujevac, Serbia
| | - Biljana Šmit
- University of Kragujevac, Institute for Information Technologies, Department of Science, Kragujevac, Serbia)
| | - Sanja Matić
- University of Kragujevac, Institute for Information Technologies, Department of Science, Kragujevac, Serbia)
| | - Matias A Alvarez-Saavedra
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, USA
- Department of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Department of Materials Science and Engineering, Northwestern University, Chicago, IL, 60208, USA
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, 60208, USA)
| | - Ivan Čapo
- Department of Histology and Embryology, Medical Faculty of Novi Sad, Novi Sad, Serbia
| | - Curtis E Moore
- Department of Chemistry & Biochemistry, The Ohio State University, 1100 W. 18th Avenue, Columbus, OH, 43210, USA
| | - Samuel I Stupp
- Department of Chemistry, Northwestern University, Evanston, IL, 60208, USA
- Simpson Querrey Institute for BioNanotechnology, Northwestern University, Chicago, IL, 60611, USA
- Department of Medicine, Northwestern University, Chicago, IL, 60611, USA
- Department of Materials Science and Engineering, Northwestern University, Chicago, IL, 60208, USA
- Department of Biomedical Engineering, Northwestern University, Chicago, IL, 60208, USA)
| | - Jovica D Badjić
- Department of Chemistry & Biochemistry, The Ohio State University, 1100 W. 18th Avenue, Columbus, OH, 43210, USA
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25
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Zhai R, Wang Z, Chai Z, Niu X, Li C, Jin C, Hu Y. Distinct activation mechanisms of β-arrestin-1 revealed by 19F NMR spectroscopy. Nat Commun 2023; 14:7865. [PMID: 38030602 PMCID: PMC10686989 DOI: 10.1038/s41467-023-43694-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Accepted: 11/16/2023] [Indexed: 12/01/2023] Open
Abstract
β-Arrestins (βarrs) are functionally versatile proteins that play critical roles in the G-protein-coupled receptor (GPCR) signaling pathways. While it is well established that the phosphorylated receptor tail plays a central role in βarr activation, emerging evidence highlights the contribution from membrane lipids. However, detailed molecular mechanisms of βarr activation by different binding partners remain elusive. In this work, we present a comprehensive study of the structural changes in critical regions of βarr1 during activation using 19F NMR spectroscopy. We show that phosphopeptides derived from different classes of GPCRs display different βarr1 activation abilities, whereas binding of the membrane phosphoinositide PIP2 stabilizes a distinct partially activated conformational state. Our results further unveil a sparsely-populated activation intermediate as well as complex cross-talks between different binding partners, implying a highly multifaceted conformational energy landscape of βarr1 that can be intricately modulated during signaling.
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Affiliation(s)
- Ruibo Zhai
- School of Life Sciences, Peking University, Beijing, 100871, China
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, 100871, China
| | - Zhuoqi Wang
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, 100871, China
- College of Chemistry and Molecular Engineering and Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, China
| | - Zhaofei Chai
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
- Joint Laboratory of the National Centers for Magnetic Resonance in Wuhan and in Beijing, Wuhan, 430071, China
| | - Xiaogang Niu
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, 100871, China
- College of Chemistry and Molecular Engineering and Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, China
| | - Conggang Li
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China
- Joint Laboratory of the National Centers for Magnetic Resonance in Wuhan and in Beijing, Wuhan, 430071, China
| | - Changwen Jin
- School of Life Sciences, Peking University, Beijing, 100871, China.
- Beijing Nuclear Magnetic Resonance Center, Peking University, Beijing, 100871, China.
- College of Chemistry and Molecular Engineering and Beijing National Laboratory for Molecular Sciences, Peking University, Beijing, 100871, China.
- Joint Laboratory of the National Centers for Magnetic Resonance in Wuhan and in Beijing, Wuhan, 430071, China.
| | - Yunfei Hu
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan, 430071, China.
- Joint Laboratory of the National Centers for Magnetic Resonance in Wuhan and in Beijing, Wuhan, 430071, China.
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26
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Shukla VK, Heller GT, Hansen DF. Biomolecular NMR spectroscopy in the era of artificial intelligence. Structure 2023; 31:1360-1374. [PMID: 37848030 DOI: 10.1016/j.str.2023.09.011] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/15/2023] [Accepted: 09/21/2023] [Indexed: 10/19/2023]
Abstract
Biomolecular nuclear magnetic resonance (NMR) spectroscopy and artificial intelligence (AI) have a burgeoning synergy. Deep learning-based structural predictors have forever changed structural biology, yet these tools currently face limitations in accurately characterizing protein dynamics, allostery, and conformational heterogeneity. We begin by highlighting the unique abilities of biomolecular NMR spectroscopy to complement AI-based structural predictions toward addressing these knowledge gaps. We then highlight the direct integration of deep learning approaches into biomolecular NMR methods. AI-based tools can dramatically improve the acquisition and analysis of NMR spectra, enhancing the accuracy and reliability of NMR measurements, thus streamlining experimental processes. Additionally, deep learning enables the development of novel types of NMR experiments that were previously unattainable, expanding the scope and potential of biomolecular NMR spectroscopy. Ultimately, a combination of AI and NMR promises to further revolutionize structural biology on several levels, advance our understanding of complex biomolecular systems, and accelerate drug discovery efforts.
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Affiliation(s)
- Vaibhav Kumar Shukla
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK
| | - Gabriella T Heller
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK.
| | - D Flemming Hansen
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London WC1E 6BT, UK.
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27
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Koscielniak J, Li J, Sail D, Swenson R, Anklin C, Rozovsky S, Byrd RA. Exploring Sulfur Sites in Proteins via Triple-Resonance 1H-Detected 77Se NMR. J Am Chem Soc 2023; 145. [PMID: 37906952 PMCID: PMC10655107 DOI: 10.1021/jacs.3c07225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/11/2023] [Accepted: 10/12/2023] [Indexed: 11/02/2023]
Abstract
NMR spectroscopy has been applied to virtually all sites within proteins and biomolecules; however, the observation of sulfur sites remains very challenging. Recent studies have examined 77Se as a replacement for sulfur and applied 77Se NMR in both the solution and solid states. As a spin-1/2 nuclide, 77Se is attractive as a probe of sulfur sites, and it has a very large chemical shift range (due to a large chemical shift anisotropy), which makes it potentially very sensitive to structural and/or binding interactions as well as dynamics. Despite being a spin-1/2 nuclide, there have been rather limited studies of 77Se, and the ability to use 1H-indirect detection has been sparse. Some examples exist, but in the absence of a directly bonded, nonexchangeable 1H, these have been largely limited to smaller molecules. We develop and illustrate approaches using double-labeling of 13C and 77Se in proteins that enable more sensitive triple-resonance schemes via multistep coherence transfers and 1H-detection. These methods require specialized hardware and decoupling schemes, which we developed and will be discussed.
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Affiliation(s)
- Janusz Koscielniak
- Leidos
Biomedical Research, Inc., Frederick, Maryland 21702, United States
| | - Jess Li
- Center
for Structural Biology, National Cancer
Institute, Frederick, Maryland 21702-1201, United States
| | - Deepak Sail
- Chemistry
and Synthesis Center, National Heart Lung
and Blood Institute, Bethesda, Maryland 20814, United States
| | - Rolf Swenson
- Chemistry
and Synthesis Center, National Heart Lung
and Blood Institute, Bethesda, Maryland 20814, United States
| | - Clemens Anklin
- Bruker
BioSpin Corp., Billerica, Massachusetts 01821, United States
| | - Sharon Rozovsky
- Department
of Chemistry and Biochemistry, University
of Delaware, Newark, Delaware 19716, United States
| | - R. Andrew Byrd
- Center
for Structural Biology, National Cancer
Institute, Frederick, Maryland 21702-1201, United States
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28
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Dani R, Pawloski W, Chaurasiya DK, Srilatha NS, Agarwal S, Fushman D, Naganathan AN. Conformational Tuning Shapes the Balance between Functional Promiscuity and Specialization in Paralogous Plasmodium Acyl-CoA Binding Proteins. Biochemistry 2023; 62:2982-2996. [PMID: 37788430 PMCID: PMC10774088 DOI: 10.1021/acs.biochem.3c00449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
Paralogous proteins confer enhanced fitness to organisms via complex sequence-conformation codes that shape functional divergence, specialization, or promiscuity. Here, we dissect the underlying mechanism of promiscuous binding versus partial subfunctionalization in paralogues by studying structurally identical acyl-CoA binding proteins (ACBPs) from Plasmodium falciparum that serve as promising drug targets due to their high expression during the protozoan proliferative phase. Combining spectroscopic measurements, solution NMR, SPR, and simulations on two of the paralogues, A16 and A749, we show that minor sequence differences shape nearly every local and global conformational feature. A749 displays a broader and heterogeneous native ensemble, weaker thermodynamic coupling and cooperativity, enhanced fluctuations, and a larger binding pocket volume compared to A16. Site-specific tryptophan probes signal a graded reduction in the sampling of substates in the holo form, which is particularly apparent in A749. The paralogues exhibit a spectrum of binding affinities to different acyl-CoAs with A749, the more promiscuous and hence the likely ancestor, binding 1000-fold stronger to lauroyl-CoA under physiological conditions. We thus demonstrate how minor sequence changes modulate the extent of long-range interactions and dynamics, effectively contributing to the molecular evolution of contrasting functional repertoires in paralogues.
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Affiliation(s)
- Rahul Dani
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Westley Pawloski
- Center for Biomolecular Structure & Organization, Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Dhruv Kumar Chaurasiya
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | | | - Sonal Agarwal
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - David Fushman
- Center for Biomolecular Structure & Organization, Department of Chemistry & Biochemistry, University of Maryland, College Park, Maryland 20742, United States
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
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29
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Prosser RS, Alonzi NA. Discerning conformational dynamics and binding kinetics of GPCRs by 19F NMR. Curr Opin Pharmacol 2023; 72:102377. [PMID: 37612172 DOI: 10.1016/j.coph.2023.102377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 03/08/2023] [Accepted: 03/13/2023] [Indexed: 08/25/2023]
Abstract
19F NMR provides a way of monitoring conformational dynamics of G-protein coupled receptors (GPCRs) from the perspective of an ensemble. While X-ray crystallography provides exquisitely resolved high-resolution structures of specific states, it generally does not recapitulate the true ensemble of functional states. Fluorine (19F) NMR provides a highly sensitive spectroscopic window into the conformational ensemble, generally permitting the direct quantification of resolvable states. Moreover, straightforward T1- and T2-based relaxation experiments allow for the study of fluctuations within a given state and exchange between states, on timescales spanning nanoseconds to seconds. Conveniently, most biological systems are free of fluorine. Thus, via fluorinated amino acid analogues or thiol-reactive fluorinated tags, F or CF3 reporters can be site specifically incorporated into proteins of interest. In this review, fluorine labeling protocols and 19F NMR experiments will be presented, from the perspective of small molecule NMR (i.e. drug or small molecule interactions with receptors) or macromolecular NMR (i.e. conformational dynamics of receptors and receptor-G-protein complexes).
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Affiliation(s)
- R S Prosser
- Chemistry Department, University of Toronto, CPS UTM, Davis Building, Rm 4052, 3359 Mississauga Rd North, Mississauga, Ontario, L5L 1C6, Canada; Biochemistry Department, University of Toronto, CPS UTM, Davis Building, Rm 4052, 3359 Mississauga Rd North, Mississauga, Ontario, L5L 1C6, Canada.
| | - Nicholas A Alonzi
- Chemistry Department, University of Toronto, CPS UTM, Davis Building, Rm 4052, 3359 Mississauga Rd North, Mississauga, Ontario, L5L 1C6, Canada
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30
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Hansen AL, Xiang X, Yuan C, Bruschweiler-Li L, Brüschweiler R. Excited-state observation of active K-Ras reveals differential structural dynamics of wild-type versus oncogenic G12D and G12C mutants. Nat Struct Mol Biol 2023; 30:1446-1455. [PMID: 37640864 PMCID: PMC10584678 DOI: 10.1038/s41594-023-01070-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 07/17/2023] [Indexed: 08/31/2023]
Abstract
Despite the prominent role of the K-Ras protein in many different types of human cancer, major gaps in atomic-level information severely limit our understanding of its functions in health and disease. Here, we report the quantitative backbone structural dynamics of K-Ras by solution nuclear magnetic resonance spectroscopy of the active state of wild-type K-Ras bound to guanosine triphosphate (GTP) nucleotide and two of its oncogenic P-loop mutants, G12D and G12C, using a new nanoparticle-assisted spin relaxation method, relaxation dispersion and chemical exchange saturation transfer experiments covering the entire range of timescales from picoseconds to milliseconds. Our combined experiments allow detection and analysis of the functionally critical Switch I and Switch II regions, which have previously remained largely unobservable by X-ray crystallography and nuclear magnetic resonance spectroscopy. Our data reveal cooperative transitions of K-Ras·GTP to a highly dynamic excited state that closely resembles the partially disordered K-Ras·GDP state. These results advance our understanding of differential GTPase activities and signaling properties of the wild type versus mutants and may thus guide new strategies for the development of therapeutics.
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Affiliation(s)
- Alexandar L Hansen
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, USA
| | - Xinyao Xiang
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA
| | - Chunhua Yuan
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, USA
| | - Lei Bruschweiler-Li
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, USA.
| | - Rafael Brüschweiler
- Campus Chemical Instrument Center, The Ohio State University, Columbus, OH, USA.
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH, USA.
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, USA.
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31
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Kumar A, Madhurima K, Naganathan AN, Vallurupalli P, Sekhar A. Probing excited state 1Hα chemical shifts in intrinsically disordered proteins with a triple resonance-based CEST experiment: Application to a disorder-to-order switch. Methods 2023; 218:198-209. [PMID: 37607621 PMCID: PMC7615522 DOI: 10.1016/j.ymeth.2023.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Revised: 08/14/2023] [Accepted: 08/16/2023] [Indexed: 08/24/2023] Open
Abstract
Over 40% of eukaryotic proteomes and 15% of bacterial proteomes are predicted to be intrinsically disordered based on their amino acid sequence. Intrinsically disordered proteins (IDPs) exist as heterogeneous ensembles of interconverting conformations and pose a challenge to the structure-function paradigm by apparently functioning without possessing stable structural elements. IDPs play a prominent role in biological processes involving extensive intermolecular interaction networks and their inherently dynamic nature facilitates their promiscuous interaction with multiple structurally diverse partner molecules. NMR spectroscopy has made pivotal contributions to our understanding of IDPs because of its unique ability to characterize heterogeneity at atomic resolution. NMR methods such as Chemical Exchange Saturation Transfer (CEST) and relaxation dispersion have enabled the detection of 'invisible' excited states in biomolecules which are transiently and sparsely populated, yet central for function. Here, we develop a 1Hα CEST pulse sequence which overcomes the resonance overlap problem in the 1Hα-13Cα plane of IDPs by taking advantage of the superior resolution in the 1H-15N correlation spectrum. In this sequence, magnetization is transferred after 1H CEST using a triple resonance coherence transfer pathway from 1Hα (i) to 1HN(i + 1) during which the 15N(t1) and 1HN(t2) are frequency labelled. This approach is integrated with spin state-selective CEST for eliminating spurious dips in CEST profiles resulting from dipolar cross-relaxation. We apply this sequence to determine the excited state 1Hα chemical shifts of the intrinsically disordered DNA binding domain (CytRN) of the bacterial cytidine repressor (CytR), which transiently acquires a functional globally folded conformation. The structure of the excited state, calculated using 1Hα chemical shifts in conjunction with other excited state NMR restraints, is a three-helix bundle incorporating a helix-turn-helix motif that is vital for binding DNA.
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Affiliation(s)
- Ajith Kumar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Kulkarni Madhurima
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, Karnataka, India
| | - Athi N Naganathan
- Department of Biotechnology, Bhupat & Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Pramodh Vallurupalli
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad 500046, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, Karnataka, India.
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32
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Hommel U, Hurth K, Rondeau JM, Vulpetti A, Ostermeier D, Boettcher A, Brady JP, Hediger M, Lehmann S, Koch E, Blechschmidt A, Yamamoto R, Tundo Dottorello V, Haenni-Holzinger S, Kaiser C, Lehr P, Lingel A, Mureddu L, Schleberger C, Blank J, Ramage P, Freuler F, Eder J, Bornancin F. Discovery of a selective and biologically active low-molecular weight antagonist of human interleukin-1β. Nat Commun 2023; 14:5497. [PMID: 37679328 PMCID: PMC10484922 DOI: 10.1038/s41467-023-41190-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 08/25/2023] [Indexed: 09/09/2023] Open
Abstract
Human interleukin-1β (hIL-1β) is a pro-inflammatory cytokine involved in many diseases. While hIL-1β directed antibodies have shown clinical benefit, an orally available low-molecular weight antagonist is still elusive, limiting the applications of hIL-1β-directed therapies. Here we describe the discovery of a low-molecular weight hIL-1β antagonist that blocks the interaction with the IL-1R1 receptor. Starting from a low affinity fragment-based screening hit 1, structure-based optimization resulted in a compound (S)-2 that binds and antagonizes hIL-1β with single-digit micromolar activity in biophysical, biochemical, and cellular assays. X-ray analysis reveals an allosteric mode of action that involves a hitherto unknown binding site in hIL-1β encompassing two loops involved in hIL-1R1/hIL-1β interactions. We show that residues of this binding site are part of a conformationally excited state of the mature cytokine. The compound antagonizes hIL-1β function in cells, including primary human fibroblasts, demonstrating the relevance of this discovery for future development of hIL-1β directed therapeutics.
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Affiliation(s)
- Ulrich Hommel
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland.
| | - Konstanze Hurth
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland.
| | - Jean-Michel Rondeau
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Anna Vulpetti
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Daniela Ostermeier
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Andreas Boettcher
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Jacob Peter Brady
- Novartis Institutes for BioMedical Research, 250 Massachusetts Avenue, Cambridge, MA, 02139, USA
| | - Michael Hediger
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Sylvie Lehmann
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Elke Koch
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Anke Blechschmidt
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Rina Yamamoto
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | | | | | - Christian Kaiser
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Philipp Lehr
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Andreas Lingel
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Luca Mureddu
- Leicester Institute of Structural and Chemical Biology, Department of Molecular and Cell Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Christian Schleberger
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Jutta Blank
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Paul Ramage
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Felix Freuler
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Joerg Eder
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland
| | - Frédéric Bornancin
- Novartis Institutes for BioMedical Research, Novartis Campus, CH-4002, Basel, Switzerland.
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33
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Tužinčin D, Padrta P, Šanderová H, Rabatinová A, Bendová K, Krásný L, Žídek L, Kadeřávek P. Characterization of a transitionally occupied state and thermal unfolding of domain 1.1 of σ A factor of RNA polymerase from Bacillus subtilis. Proteins 2023; 91:1276-1287. [PMID: 37350110 DOI: 10.1002/prot.26531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 05/06/2023] [Accepted: 05/10/2023] [Indexed: 06/24/2023]
Abstract
σ factors are essential parts of bacterial RNA polymerase (RNAP) as they allow to recognize promotor sequences and initiate transcription. Domain 1.1 of vegetative σ factors occupies the primary channel of RNAP and also prevents binding of the σ factor to promoter DNA alone. Here, we show that domain 1.1 of Bacillus subtilisσ A exists in more structurally distinct variants in dynamic equilibrium. The major conformation at room temperature is represented by a previously reported well-folded structure solved by nuclear magnetic resonance (NMR), but 4% of the protein molecules are present in a less thermodynamically favorable state. We show that this population increases with temperature and we predict its significant elevation at higher but still biologically relevant temperatures. We characterized the minor state of the domain 1.1 using specialized methods of NMR. We found that, in contrast to the major state, the detected minor state is partially unfolded. Its propensity to form secondary structure elements is especially decreased for the first and third α helices, while the second α helix and β strand close to the C-terminus are more stable. We also analyzed thermal unfolding of the domain 1.1 and performed functional experiments with full lengthσ A and its shortened version lacking domain 1.1 (σ A _ Δ 1.1 ). The results revealed that while full lengthσ A increases transcription activity of RNAP with increasing temperature, transcription withσ A _ Δ 1.1 remains constant. In summary, this study reveals conformational dynamics of domain 1.1 and provides a basis for studies of its interaction with RNAP and effects on transcription regulation.
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Affiliation(s)
- Dávid Tužinčin
- National Centre for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Petr Padrta
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Hana Šanderová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Alžběta Rabatinová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Kateřina Bendová
- National Centre for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Libor Krásný
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Lukáš Žídek
- National Centre for Biomolecular Research (NCBR), Faculty of Science, Masaryk University, Brno, Czech Republic
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
| | - Pavel Kadeřávek
- Central European Institute of Technology (CEITEC), Masaryk University, Brno, Czech Republic
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34
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Kwok E, Otto SC, Khuu P, Carpenter AP, Codding SJ, Reardon PN, Vanegas J, Kumar TM, Kuykendall CJ, Mehl RA, Baio J, Johnson CP. The Dysferlin C2A Domain Binds PI(4,5)P2 and Penetrates Membranes. J Mol Biol 2023; 435:168193. [PMID: 37406927 PMCID: PMC10699586 DOI: 10.1016/j.jmb.2023.168193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 06/22/2023] [Accepted: 06/27/2023] [Indexed: 07/07/2023]
Abstract
Dysferlin is a large membrane protein found most prominently in striated muscle. Loss of dysferlin activity is associated with reduced exocytosis, abnormal intracellular Ca2+ and the muscle diseases limb-girdle muscular dystrophy and Miyoshi myopathy. The cytosolic region of dysferlin consists of seven C2 domains with mutations in the C2A domain at the N-terminus resulting in pathology. Despite the importance of Ca2+ and membrane binding activities of the C2A domain for dysferlin function, the mechanism of the domain remains poorly characterized. In this study we find that the C2A domain preferentially binds membranes containing PI(4,5)P2 through an interaction mediated by residues Y23, K32, K33, and R77 on the concave face of the domain. We also found that subsequent to membrane binding, the C2A domain inserts residues on the Ca2+ binding loops into the membrane. Analysis of solution NMR measurements indicate that the domain inhabits two distinct structural states, with Ca2+ shifting the population between states towards a more rigid structure with greater affinity for PI(4,5)P2. Based on our results, we propose a mechanism where Ca2+ converts C2A from a structurally dynamic, low PI(4,5)P2 affinity state to a high affinity state that targets dysferlin to PI(4,5)P2 enriched membranes through interaction with Tyr23, K32, K33, and R77. Binding also involves changes in lipid packing and insertion by the third Ca2+ binding loop of the C2 domain into the membrane, which would contribute to dysferlin function in exocytosis and Ca2+ regulation.
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Affiliation(s)
- Ethiene Kwok
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Shauna C Otto
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Patricia Khuu
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Andrew P Carpenter
- Department of Chemical Engineering, Oregon State University, Corvallis, OR 97331, USA
| | - Sara J Codding
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | | | - Juan Vanegas
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Tanushri M Kumar
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Chapman J Kuykendall
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Ryan A Mehl
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA
| | - Joe Baio
- Department of Chemical Engineering, Oregon State University, Corvallis, OR 97331, USA
| | - Colin P Johnson
- Department of Biochemistry and Biophysics, Oregon State University, Corvallis, OR 97331, USA.
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35
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Zinke M, Lejeune M, Mechaly A, Bardiaux B, Boneca IG, Delepelaire P, Izadi-Pruneyre N. Ton Motor Conformational Switch and Peptidoglycan Role in Bacterial Nutrient Uptake. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.11.552980. [PMID: 37609138 PMCID: PMC10441417 DOI: 10.1101/2023.08.11.552980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Active nutrient uptake is fundamental for survival and pathogenicity of Gram-negative bacteria, which operate a multi-protein Ton system to transport essential nutrients like metals and vitamins. This system harnesses the proton motive force at the inner membrane to energize the import through the outer membrane, but the mechanism of energy transfer remains enigmatic. Here, we study the periplasmic domain of ExbD, a crucial component of the proton channel of the Ton system. We show that this domain is a dynamic dimer switching between two conformations representing the proton channel's open and closed states. By in vivo phenotypic assays we demonstrate that this conformational switch is essential for the nutrient uptake by bacteria. The open state of ExbD triggers a disorder to order transition of TonB, enabling TonB to supply energy to the nutrient transporter. We also reveal the anchoring role of the peptidoglycan layer in this mechanism. Herein, we propose a mechanistic model for the Ton system, emphasizing ExbD duality and the pivotal catalytic role of peptidoglycan. Sequence analysis suggests that this mechanism is conserved in other systems energizing gliding motility and membrane integrity. Our study fills important gaps in understanding bacterial motor mechanism and proposes novel antibacterial strategies.
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Affiliation(s)
- Maximilian Zinke
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015 Paris, France
| | - Maylis Lejeune
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015 Paris, France
| | - Ariel Mechaly
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Crystallography Platform, F-75015 Paris, France
| | - Benjamin Bardiaux
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015 Paris, France
| | - Ivo Gomperts Boneca
- Institut Pasteur, Université Paris Cité, CNRS UMR6047, INSERM U1306, Unité de Biologie et génétique de la paroi bactérienne F-75015, Paris, France
| | - Philippe Delepelaire
- Laboratoire de Biologie Physico-Chimique des Protéines Membranaires, Université Paris Cité, UMR7099 CNRS, F-75005, Paris, France
- Institut de Biologie Physico-Chimique, F-75005, Paris, France
| | - Nadia Izadi-Pruneyre
- Institut Pasteur, Université Paris Cité, CNRS UMR3528, Bacterial Transmembrane Systems Unit, F-75015 Paris, France
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36
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Khandave NP, Sekhar A, Vallurupalli P. Studying micro to millisecond protein dynamics using simple amide 15N CEST experiments supplemented with major-state R 2 and visible peak-position constraints. JOURNAL OF BIOMOLECULAR NMR 2023; 77:165-181. [PMID: 37300639 PMCID: PMC7615914 DOI: 10.1007/s10858-023-00419-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/10/2023] [Indexed: 06/12/2023]
Abstract
Over the last decade amide 15N CEST experiments have emerged as a popular tool to study protein dynamics that involves exchange between a 'visible' major state and sparsely populated 'invisible' minor states. Although initially introduced to study exchange between states that are in slow exchange with each other (typical exchange rates of, 10 to 400 s-1), they are now used to study interconversion between states on the intermediate to fast exchange timescale while still using low to moderate (5 to 350 Hz) 'saturating' B1 fields. The 15N CEST experiment is very sensitive to exchange as the exchange delay TEX can be quite long (~0.5 s) allowing for a large number of exchange events to occur making it a very powerful tool to detect minor sates populated ([Formula: see text]) to as low as 1%. When systems are in fast exchange and the 15N CEST data has to be described using a model that contains exchange, the exchange parameters are often poorly defined because the [Formula: see text] versus [Formula: see text] and [Formula: see text] versus exchange rate ([Formula: see text]) plots can be quite flat with shallow or no minima and the analysis of such 15N CEST data can lead to wrong estimates of the exchange parameters due to the presence of 'spurious' minima. Here we show that the inclusion of experimentally derived constraints on the intrinsic transverse relaxation rates and the inclusion of visible state peak-positions during the analysis of amide 15N CEST data acquired with moderate B1 values (~50 to ~350 Hz) results in convincing minima in the [Formula: see text] versus [Formula: see text] and the [Formula: see text] versus [Formula: see text] plots even when exchange occurs on the 100 μs timescale. The utility of this strategy is demonstrated on the fast-folding Bacillus stearothermophilus peripheral subunit binding domain that folds with a rate constant ~104 s-1. Here the analysis of 15N CEST data alone results in [Formula: see text] versus [Formula: see text] and [Formula: see text] versus [Formula: see text] plots that contain shallow minima, but the inclusion of visible-state peak positions and restraints on the intrinsic transverse relaxation rates of both states during the analysis of the 15N CEST data results in pronounced minima in the [Formula: see text] versus [Formula: see text] and [Formula: see text] versus [Formula: see text] plots and precise exchange parameters even in the fast exchange regime ([Formula: see text]~5). Using this strategy we find that the folding rate constant of PSBD is invariant (~10,500 s-1) from 33.2 to 42.9 °C while the unfolding rates (~70 to ~500 s-1) and unfolded state populations (~0.7 to ~4.3%) increase with temperature. The results presented here show that protein dynamics occurring on the 10 to 104 s-1 timescale can be studied using amide 15N CEST experiments.
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Affiliation(s)
- Nihar Pradeep Khandave
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500046, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science, Bengaluru, Karnataka, 560012, India
| | - Pramodh Vallurupalli
- Tata Institute of Fundamental Research Hyderabad, 36/P, Gopanpally Village, Serilingampally Mandal, Ranga Reddy District, Hyderabad, 500046, India.
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37
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Singh H, Das CK, Buchmuller BC, Schäfer LV, Summerer D, Linser R. Epigenetic CpG duplex marks probed by an evolved DNA reader via a well-tempered conformational plasticity. Nucleic Acids Res 2023; 51:6495-6506. [PMID: 36919612 PMCID: PMC10325892 DOI: 10.1093/nar/gkad134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 01/14/2023] [Accepted: 02/15/2023] [Indexed: 03/16/2023] Open
Abstract
5-methylcytosine (mC) and its TET-oxidized derivatives exist in CpG dyads of mammalian DNA and regulate cell fate, but how their individual combinations in the two strands of a CpG act as distinct regulatory signals is poorly understood. Readers that selectively recognize such novel 'CpG duplex marks' could be versatile tools for studying their biological functions, but their design represents an unprecedented selectivity challenge. By mutational studies, NMR relaxation, and MD simulations, we here show that the selectivity of the first designer reader for an oxidized CpG duplex mark hinges on precisely tempered conformational plasticity of the scaffold adopted during directed evolution. Our observations reveal the critical aspect of defined motional features in this novel reader for affinity and specificity in the DNA/protein interaction, providing unexpected prospects for further design progress in this novel area of DNA recognition.
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Affiliation(s)
- Himanshu Singh
- Department of Chemistry and Chemical Biology, Technical University Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
| | - Chandan K Das
- Theoretical Chemistry, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Benjamin C Buchmuller
- Department of Chemistry and Chemical Biology, Technical University Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
| | - Lars V Schäfer
- Theoretical Chemistry, Ruhr University Bochum, Universitätsstr. 150, 44801 Bochum, Germany
| | - Daniel Summerer
- Department of Chemistry and Chemical Biology, Technical University Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
| | - Rasmus Linser
- Department of Chemistry and Chemical Biology, Technical University Dortmund, Otto-Hahn-Str. 4a, 44227 Dortmund, Germany
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38
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Madhurima K, Nandi B, Munshi S, Naganathan AN, Sekhar A. Functional regulation of an intrinsically disordered protein via a conformationally excited state. SCIENCE ADVANCES 2023; 9:eadh4591. [PMID: 37379390 PMCID: PMC10306299 DOI: 10.1126/sciadv.adh4591] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 05/23/2023] [Indexed: 06/30/2023]
Abstract
A longstanding goal in the field of intrinsically disordered proteins (IDPs) is to characterize their structural heterogeneity and pinpoint the role of this heterogeneity in IDP function. Here, we use multinuclear chemical exchange saturation (CEST) nuclear magnetic resonance to determine the structure of a thermally accessible globally folded excited state in equilibrium with the intrinsically disordered native ensemble of a bacterial transcriptional regulator CytR. We further provide evidence from double resonance CEST experiments that the excited state, which structurally resembles the DNA-bound form of cytidine repressor (CytR), recognizes DNA by means of a "folding-before-binding" conformational selection pathway. The disorder-to-order regulatory switch in DNA recognition by natively disordered CytR therefore operates through a dynamical variant of the lock-and-key mechanism where the structurally complementary conformation is transiently accessed via thermal fluctuations.
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Affiliation(s)
- Kulkarni Madhurima
- Molecular Biophysics Unit, Indian Institute of Science Bangalore, Bengaluru 560 012, India
| | - Bodhisatwa Nandi
- Molecular Biophysics Unit, Indian Institute of Science Bangalore, Bengaluru 560 012, India
| | - Sneha Munshi
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Athi N. Naganathan
- Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036, India
| | - Ashok Sekhar
- Molecular Biophysics Unit, Indian Institute of Science Bangalore, Bengaluru 560 012, India
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39
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Overbeck JH, Vögele J, Nussbaumer F, Duchardt‐Ferner E, Kreutz C, Wöhnert J, Sprangers R. 19F NMR Untersuchung des Konformationsaustauschs mehrerer Zustände im synthetischen Neomycin-bindenden Riboschalter. ANGEWANDTE CHEMIE (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2023; 135:e202218064. [PMID: 38516132 PMCID: PMC10953372 DOI: 10.1002/ange.202218064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Indexed: 03/29/2023]
Abstract
AbstractDer synthetische Neomycin‐bindende Riboschalter interagiert mit seinem Liganden Neomycin sowie mit den verwandten Antibiotika Ribostamycin und Paromomycin. Die Bindung dieser Aminoglykoside induziert sehr ähnliche Grundzustandsstrukturen in der RNA, allerdings kann nur Neomycin die Initiierung der Translation effizient unterdrücken. Der molekulare Ursprung dieser Unterschiede wurde auf Unterschiede in der Dynamik der Ligand‐Riboschalter‐Komplexe zurückgeführt. In diesem Artikel kombinieren wir fünf komplementäre fluorbasierte NMR‐Methoden, um die Dynamik der drei Riboschalter‐Komplexe im Sekunden‐ bis Mikrosekundenbereich genau zu quantifizieren. Unsere Daten offenbaren komplexe Austauschprozesse mit bis zu vier strukturell unterschiedlichen Zuständen. Wir interpretieren unsere Ergebnisse in einem Modell, das ein Zusammenspiel zwischen verschiedenen chemischen Gruppen in den Antibiotika und spezifischen Basen im Riboschalter zeigt. Allgemeiner unterstreichen unsere Daten das Potenzial von 19F NMR‐Methoden, komplexe Austauschprozesse mit mehreren angeregten Zuständen zu charakterisieren.
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Affiliation(s)
- Jan H. Overbeck
- Department of Biophysics IRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193051RegensburgDeutschland
| | - Jennifer Vögele
- Institute for Molecular BiosciencesGoethe-University FrankfurtMax-von-Laue-Str. 960438Frankfurt/M.Deutschland
| | - Felix Nussbaumer
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnsbruckÖsterreich
| | - Elke Duchardt‐Ferner
- Institute for Molecular BiosciencesGoethe-University FrankfurtMax-von-Laue-Str. 960438Frankfurt/M.Deutschland
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnsbruckÖsterreich
| | - Jens Wöhnert
- Institute for Molecular BiosciencesGoethe-University FrankfurtMax-von-Laue-Str. 960438Frankfurt/M.Deutschland
| | - Remco Sprangers
- Department of Biophysics IRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193051RegensburgDeutschland
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40
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Overbeck JH, Vögele J, Nussbaumer F, Duchardt‐Ferner E, Kreutz C, Wöhnert J, Sprangers R. Multi-Site Conformational Exchange in the Synthetic Neomycin-Sensing Riboswitch Studied by 19 F NMR. Angew Chem Int Ed Engl 2023; 62:e202218064. [PMID: 36970768 PMCID: PMC10952710 DOI: 10.1002/anie.202218064] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 02/24/2023] [Accepted: 03/22/2023] [Indexed: 03/28/2023]
Abstract
The synthetic neomycin-sensing riboswitch interacts with its cognate ligand neomycin as well as with the related antibiotics ribostamycin and paromomycin. Binding of these aminoglycosides induces a very similar ground state structure in the RNA, however, only neomycin can efficiently repress translation initiation. The molecular origin of these differences has been traced back to differences in the dynamics of the ligand:riboswitch complexes. Here, we combine five complementary fluorine based NMR methods to accurately quantify seconds to microseconds dynamics in the three riboswitch complexes. Our data reveal complex exchange processes with up to four structurally different states. We interpret our findings in a model that shows an interplay between different chemical groups in the antibiotics and specific bases in the riboswitch. More generally, our data underscore the potential of 19 F NMR methods to characterize complex exchange processes with multiple excited states.
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Affiliation(s)
- Jan H. Overbeck
- Department of Biophysics IRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193051RegensburgGermany
| | - Jennifer Vögele
- Institute for Molecular BiosciencesGoethe-University FrankfurtMax-von-Laue-Str. 960438Frankfurt/M.Germany
| | - Felix Nussbaumer
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnsbruckAustria
| | - Elke Duchardt‐Ferner
- Institute for Molecular BiosciencesGoethe-University FrankfurtMax-von-Laue-Str. 960438Frankfurt/M.Germany
| | - Christoph Kreutz
- Institute of Organic Chemistry and Center for Molecular Biosciences Innsbruck (CMBI)University of InnsbruckInnsbruckAustria
| | - Jens Wöhnert
- Institute for Molecular BiosciencesGoethe-University FrankfurtMax-von-Laue-Str. 960438Frankfurt/M.Germany
| | - Remco Sprangers
- Department of Biophysics IRegensburg Center for BiochemistryUniversity of RegensburgUniversitätsstrasse 3193051RegensburgGermany
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41
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Rennella E, Sahtoe DD, Baker D, Kay LE. Exploiting conformational dynamics to modulate the function of designed proteins. Proc Natl Acad Sci U S A 2023; 120:e2303149120. [PMID: 37094170 PMCID: PMC10161014 DOI: 10.1073/pnas.2303149120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 03/22/2023] [Indexed: 04/26/2023] Open
Abstract
With the recent success in calculating protein structures from amino acid sequences using artificial intelligence-based algorithms, an important next step is to decipher how dynamics is encoded by the primary protein sequence so as to better predict function. Such dynamics information is critical for protein design, where strategies could then focus not only on sequences that fold into particular structures that perform a given task, but would also include low-lying excited protein states that could influence the function of the designed protein. Herein, we illustrate the importance of dynamics in modulating the function of C34, a designed α/β protein that captures β-strands of target ligands and is a member of a family of proteins designed to sequester β-strands and β hairpins of aggregation-prone molecules that lead to a variety of pathologies. Using a strategy to "see" regions of apo C34 that are invisible to NMR spectroscopy as a result of pervasive conformational exchange, as well as a mutagenesis approach whereby C34 molecules are stabilized into a single conformer, we determine the structures of the predominant conformations that are sampled by C34 and show that these attenuate the affinity for cognate peptide. Subsequently, the observed motion is exploited to develop an allosterically regulated peptide binder whose binding affinity can be controlled through the addition of a second molecule. Our study emphasizes the unique role that NMR can play in directing the design process and in the construction of new molecules with more complex functionality.
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Affiliation(s)
- Enrico Rennella
- Department of Molecular Genetics, University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto, ONM5S 3H6, Canada
| | - Danny D. Sahtoe
- Department of Biochemistry, University of Washington, Seattle, WA98195
- Institute for Protein Design, University of Washington, Seattle, WA98195
- HHMI, University of Washington, Seattle, WA98195
| | - David Baker
- Department of Biochemistry, University of Washington, Seattle, WA98195
- Institute for Protein Design, University of Washington, Seattle, WA98195
- HHMI, University of Washington, Seattle, WA98195
| | - Lewis E. Kay
- Department of Molecular Genetics, University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Biochemistry, University of Toronto, Toronto, ONM5S 1A8, Canada
- Department of Chemistry, University of Toronto, Toronto, ONM5S 3H6, Canada
- Program in Molecular Medicine, The Hospital for Sick Children Research Institute, Toronto, ONM5G 0A4, Canada
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42
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Verkhivker G, Alshahrani M, Gupta G, Xiao S, Tao P. From Deep Mutational Mapping of Allosteric Protein Landscapes to Deep Learning of Allostery and Hidden Allosteric Sites: Zooming in on "Allosteric Intersection" of Biochemical and Big Data Approaches. Int J Mol Sci 2023; 24:7747. [PMID: 37175454 PMCID: PMC10178073 DOI: 10.3390/ijms24097747] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 04/22/2023] [Accepted: 04/23/2023] [Indexed: 05/15/2023] Open
Abstract
The recent advances in artificial intelligence (AI) and machine learning have driven the design of new expert systems and automated workflows that are able to model complex chemical and biological phenomena. In recent years, machine learning approaches have been developed and actively deployed to facilitate computational and experimental studies of protein dynamics and allosteric mechanisms. In this review, we discuss in detail new developments along two major directions of allosteric research through the lens of data-intensive biochemical approaches and AI-based computational methods. Despite considerable progress in applications of AI methods for protein structure and dynamics studies, the intersection between allosteric regulation, the emerging structural biology technologies and AI approaches remains largely unexplored, calling for the development of AI-augmented integrative structural biology. In this review, we focus on the latest remarkable progress in deep high-throughput mining and comprehensive mapping of allosteric protein landscapes and allosteric regulatory mechanisms as well as on the new developments in AI methods for prediction and characterization of allosteric binding sites on the proteome level. We also discuss new AI-augmented structural biology approaches that expand our knowledge of the universe of protein dynamics and allostery. We conclude with an outlook and highlight the importance of developing an open science infrastructure for machine learning studies of allosteric regulation and validation of computational approaches using integrative studies of allosteric mechanisms. The development of community-accessible tools that uniquely leverage the existing experimental and simulation knowledgebase to enable interrogation of the allosteric functions can provide a much-needed boost to further innovation and integration of experimental and computational technologies empowered by booming AI field.
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Affiliation(s)
- Gennady Verkhivker
- Keck Center for Science and Engineering, Graduate Program in Computational and Data Sciences, Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA; (M.A.); (G.G.)
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, CA 92618, USA
| | - Mohammed Alshahrani
- Keck Center for Science and Engineering, Graduate Program in Computational and Data Sciences, Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA; (M.A.); (G.G.)
| | - Grace Gupta
- Keck Center for Science and Engineering, Graduate Program in Computational and Data Sciences, Schmid College of Science and Technology, Chapman University, Orange, CA 92866, USA; (M.A.); (G.G.)
| | - Sian Xiao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX 75275, USA; (S.X.); (P.T.)
| | - Peng Tao
- Department of Chemistry, Center for Research Computing, Center for Drug Discovery, Design, and Delivery (CD4), Southern Methodist University, Dallas, TX 75275, USA; (S.X.); (P.T.)
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43
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Grün JT, Kim J, Jayanthi S, Lupulescu A, Kupče ER, Schwalbe H, Frydman L. Identifying and Overcoming Artifacts in 1 H-Based Saturation Transfer NOE NMR Experiments. J Am Chem Soc 2023; 145:6289-6298. [PMID: 36877814 PMCID: PMC10037324 DOI: 10.1021/jacs.2c13087] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
Magnetization transfer experiments are versatile nuclear magnetic resonance (NMR) tools providing site-specific information. We have recently discussed how saturation magnetization transfer (SMT) experiments could leverage repeated repolarizations arising from exchanges between labile and water protons to enhance connectivities revealed via the nuclear Overhauser effect (NOE). Repeated experience with SMT has shown that a number of artifacts may arise in these experiments, which may confound the information being sought - particularly when seeking small NOEs among closely spaced resonances. One of these pertains to what we refer to as "spill-over" effects, originating from the use of long saturation pulses leading to changes in the signals of proximate peaks. A second, related but in fact different effect, derives from what we describe as NOE "oversaturation", a phenomenon whereby the use of overtly intense RF fields overwhelms the cross-relaxation signature. The origin and ways to avoid these two effects are described. A final source of potential artifact arises in applications where the labile 1Hs of interest are bound to 15N-labeled heteronuclei. SMT's long 1H saturation times will then be usually implemented while under 15N decoupling based on cyclic schemes leading to decoupling sidebands. Although these sidebands usually remain invisible in NMR, they may lead to a very efficient saturation of the main resonance when touched by SMT frequencies. All of these phenomena are herein experimentally demonstrated, and solutions to overcome them are proposed.
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Affiliation(s)
- J Tassilo Grün
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Jihyun Kim
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Sundaresan Jayanthi
- Department of Physics, Indian Institute of Space Science and Technology, Valiamala, Thiruvananthapuram 695547, Kerala, India
| | - Adonis Lupulescu
- Extreme Light Infrastructure─Nuclear Physics, "Horia Hulubei" National Institute for Physics and Nuclear Engineering, 30 Reactorului Street, 077125 Bucharest-Măgurele, Romania
| | - E Riks Kupče
- Bruker UK Ltd., Welland House, Westwood Business Park, Coventry CV4 9GH, U.K
| | - Harald Schwalbe
- Institute for Organic Chemistry and Chemical Biology, Center for Biomolecular Magnetic Resonance, Goethe-University, 60438 Frankfurt/Main, Germany
| | - Lucio Frydman
- Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot 7610001, Israel
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44
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Bernard DN, Narayanan C, Hempel T, Bafna K, Bhojane PP, Létourneau M, Howell EE, Agarwal PK, Doucet N. Conformational exchange divergence along the evolutionary pathway of eosinophil-associated ribonucleases. Structure 2023; 31:329-342.e4. [PMID: 36649708 PMCID: PMC9992247 DOI: 10.1016/j.str.2022.12.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 11/24/2022] [Accepted: 12/20/2022] [Indexed: 01/18/2023]
Abstract
The evolutionary role of conformational exchange in the emergence and preservation of function within structural homologs remains elusive. While protein engineering has revealed the importance of flexibility in function, productive modulation of atomic-scale dynamics has only been achieved on a finite number of distinct folds. Allosteric control of unique members within dynamically diverse structural families requires a better appreciation of exchange phenomena. Here, we examined the functional and structural role of conformational exchange within eosinophil-associated ribonucleases. Biological and catalytic activity of various EARs was performed in parallel to mapping their conformational behavior on multiple timescales using NMR and computational analyses. Despite functional conservation and conformational seclusion to a specific domain, we show that EARs can display similar or distinct motional profiles, implying divergence rather than conservation of flexibility. Comparing progressively more distant enzymes should unravel how this subfamily has evolved new functions and/or altered their behavior at the molecular level.
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Affiliation(s)
- David N Bernard
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, QC H7V 1B7, Canada
| | - Chitra Narayanan
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, QC H7V 1B7, Canada; Department of Chemistry, New Jersey City University, Jersey City, NJ 07305, USA
| | - Tim Hempel
- Department of Mathematics and Computer Science, Freie Universität Berlin, Arnimallee 12, 14195 Berlin, Germany; Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
| | - Khushboo Bafna
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Purva Prashant Bhojane
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Myriam Létourneau
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, QC H7V 1B7, Canada
| | - Elizabeth E Howell
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, TN 37996, USA
| | - Pratul K Agarwal
- Department of Physiological Sciences and High-Performance Computing Center, Oklahoma State University, Stillwater, OK 74078, USA.
| | - Nicolas Doucet
- Centre Armand-Frappier Santé Biotechnologie, Institut national de la recherche scientifique (INRS), Université du Québec, 531 Boulevard des Prairies, Laval, QC H7V 1B7, Canada; PROTEO, the Québec Network for Research on Protein Function, Engineering, and Applications, Université Laval, 1045 Avenue de la Médecine, Québec, QC G1V 0A6, Canada.
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45
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Zhou X, Pang Z, Cao W, Cao Z, Zhu J, Qi Y, Peng X, Kong X. Diffusion NMR for Measuring Dynamic Ligand Exchange on Colloidal Nanocrystals. Anal Chem 2023; 95:792-801. [PMID: 36520837 DOI: 10.1021/acs.analchem.2c02964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Ligand exchange is fundamentally related to the surface chemistry of nanoparticles in solution and is also an essential procedure for their synthesis and solution processing. The solution of ligand-bearing nanoparticles can be regarded as a dynamic equilibrium of bound and free ligands depending on the concentration and temperature. The direct experimental calibration of the ligand exchange dynamics relies on the in situ and real-time quantification of bound and free ligands. However, existing analytical strategies are often with limited applicability considering the requirement of special functional groups or the indirect detection of photoluminescence or reaction heat. In this work, we explore diffusion-based methods of solution-state nuclear magnetic resonance (NMR) as a general strategy to probe ligand exchange. Using comprehensive numerical simulations, we show that diffusion NMR with designable time sequences can effectively distinguish bound and free ligands and measure the exchange rate constants from 0.5 to 200 s-1 under typical instrumental settings. These methods are demonstrated experimentally on colloidal CdSe nanocrystal systems with carboxylate or amine ligands whose exchange rates were previously undetectable. The kinetic rate constants, activation energies, and thermodynamic parameters of ligand exchange have been obtained under variable temperature conditions. We expect the diffusion NMR strategies to be generally applicable for calibrating the exchange of organic ligands on various nanoparticle systems.
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Affiliation(s)
- Xiaoqi Zhou
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Zhenfeng Pang
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Weicheng Cao
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Zhenming Cao
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Jie Zhu
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Yixin Qi
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Xiaogang Peng
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
| | - Xueqian Kong
- Department of Chemistry, Zhejiang University, Hangzhou310027, China.,Key Laboratory of Excited-State Materials of Zhejiang Province, Zhejiang University, Hangzhou310027, China
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46
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DMSO-Induced Unfolding of the Antifungal Disulfide Protein PAF and Its Inactive Variant: A Combined NMR and DSC Study. Int J Mol Sci 2023; 24:ijms24021208. [PMID: 36674720 PMCID: PMC9864379 DOI: 10.3390/ijms24021208] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/03/2023] [Accepted: 01/05/2023] [Indexed: 01/11/2023] Open
Abstract
PAF and related antifungal proteins are promising antimicrobial agents. They have highly stable folds around room temperature due to the presence of 3-4 disulfide bonds. However, unfolded states persist and contribute to the thermal equilibrium in aqueous solution, and low-populated states might influence their biological impact. To explore such equilibria during dimethyl sulfoxide (DMSO)-induced chemical unfolding, we studied PAF and its inactive variant PAFD19S using nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). According to the NMR monitoring at 310 K, the folded structures disappear above 80 v/v% DMSO concentration, while the unfolding is completely reversible. Evaluation of a few resolved peaks from viscosity-compensated 15N-1H HSQC spectra of PAF yielded ∆G = 23 ± 7 kJ/M as the average value for NMR unfolding enthalpy. The NMR-based structures of PAF and the mutant in 50 v/v% DMSO/H2O mixtures were more similar in the mixed solvents then they were in water. The 15N NMR relaxation dynamics in the same mixtures verified the rigid backbones of the NMR-visible fractions of the proteins; still, enhanced dynamics around the termini and some loops were observed. DSC monitoring of the Tm melting point showed parabolic dependence on the DMSO molar fraction and suggested that PAF is more stable than the inactive PAFD19S. The DSC experiments were irreversible due to the applied broad temperature range, but still suggestive of the endothermic unfolding of PAF.
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47
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Marasco M, Kirkpatrick JP, Nanna V, Carlomagno T. NMR Methods to Study the Dynamics of SH2 Domain-Phosphopeptide Complexes. Methods Mol Biol 2023; 2705:25-37. [PMID: 37668967 DOI: 10.1007/978-1-0716-3393-9_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
Nuclear magnetic resonance (NMR) spectroscopy is the method of choice for studying the dynamics of biological macromolecules in solution. By exploiting the intricate interplay between the effects of protein motion (both overall rotational diffusion and internal mobility) and nuclear spin relaxation, NMR allows molecular motion to be probed at atomic resolution over a wide range of timescales, including picosecond (bond vibrations and methyl-group rotations), nanosecond (loop motions and rotational diffusion), and microsecond-millisecond (ligand binding, allostery). In this chapter, we describe different NMR pulse schemes (R1, R1ρ, heteronuclear NOE, and CPMG relaxation dispersion) to characterize the dynamics of SH2 domains. As an example, we use the N-SH2 domain of protein tyrosine phosphatase SHP2 in complex with two phosphopeptides derived from immune checkpoint receptor PD-1 (ITIM and ITSM).
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Affiliation(s)
- Michelangelo Marasco
- Molecular Pharmacology Program, Sloan Kettering Institute for Cancer Research, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | | | - Vittoria Nanna
- School of Biosciences, University of Birmingham, Birmingham, UK
- BMWZ and Institute of Organic Chemistry, Leibniz University Hannover, Hannover, Germany
| | - Teresa Carlomagno
- School of Biosciences, College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK.
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48
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Zhang S, McCallum SA, Gillilan R, Wang J, Royer CA. High Pressure CPMG and CEST Reveal That Cavity Position Dictates Distinct Dynamic Disorder in the PP32 Repeat Protein. J Phys Chem B 2022; 126:10597-10607. [PMID: 36455152 PMCID: PMC10314987 DOI: 10.1021/acs.jpcb.2c05498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/05/2022]
Abstract
Given the central role of conformational dynamics in protein function, it is essential to characterize the time scales and structures associated with these transitions. High pressure (HP) perturbation favors transitions to excited states because they typically occupy a smaller molar volume, thus facilitating characterization of conformational dynamics. Repeat proteins, with their straightforward architecture, provide good models for probing the sequence dependence of protein conformational dynamics. Investigations of chemical exchange by 15N CPMG relaxation dispersion analysis revealed that introduction of a cavity via substitution of isoleucine 7 by alanine in the N-terminal capping motif of the pp32 leucine-rich repeat protein leads to pressure-dependent conformational exchange detected on the 500 μs-2 ms CPMG time scale. Exchange amplitude decreased from the N- to C-terminus, revealing a gradient of conformational exchange across the protein. In contrast, introduction of a cavity in the central core of pp32 via the L60A mutation led to pressure-induced exchange on a slower (>2 ms) time scale detected by 15N-CEST analysis. Excited state 15N chemical shifts indicated that in the excited state detected by HP CEST, the N-terminal region is mostly unfolded, while the core retains native-like structure. These HP chemical exchange measurements reveal that cavity position dictates exchange on distinct time scales, highlighting the subtle, yet central role of sequence in determining protein conformational dynamics.
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Affiliation(s)
- Siwen Zhang
- Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy NY USA 12180
| | - Scott A. McCallum
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy NY USA 12180
| | - Richard Gillilan
- Cornell High Energy Synchrotron Source, Cornell University, Ithaca, NY USA 14853
| | - Jinqiu Wang
- Graduate Program in Biochemistry and Biophysics, Rensselaer Polytechnic Institute, Troy NY USA 12180
| | - Catherine A. Royer
- Department of Biological Sciences, Rensselaer Polytechnic Institute, Troy NY USA 12180
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49
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Bolik-Coulon N, Hansen DF, Kay LE. Optimizing frequency sampling in CEST experiments. JOURNAL OF BIOMOLECULAR NMR 2022; 76:167-183. [PMID: 36192571 DOI: 10.1007/s10858-022-00403-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Accepted: 09/02/2022] [Indexed: 06/16/2023]
Abstract
For the past decade chemical exchange saturation transfer (CEST) experiments have been successfully applied to study exchange processes in biomolecules involving sparsely populated, transiently formed conformers. Initial implementations focused on extensive sampling of the CEST frequency domain, requiring significant measurement times. Here we show that the lengthy sampling schemes often used are not optimal and that reduced frequency sampling schedules can be developed without a priori knowledge of the exchange parameters, that only depend on the chosen B1 field, and, to a lesser extent, on the intrinsic transverse relaxation rates of ground state spins. The reduced sampling approach described here can be used synergistically with other methods for reducing measurement times such as those that excite multiple frequencies in the CEST dimension simultaneously, or make use of non-uniform sampling of indirectly detected time domains, to further decrease measurement times. The proposed approach is validated by analysis of simulated and experimental datasets.
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Affiliation(s)
- Nicolas Bolik-Coulon
- Department of Molecular Genetics, University of Toronto, Toronto, M5S 1A8, Canada.
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
| | - D Flemming Hansen
- Department of Structural and Molecular Biology, Division of Biosciences, University College London, London, WC1E 6BT, UK.
| | - Lewis E Kay
- Department of Molecular Genetics, University of Toronto, Toronto, M5S 1A8, Canada.
- Department of Chemistry, University of Toronto, Toronto, ON, M5S 3H6, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, M5S 1A8, Canada.
- Program in Molecular Medicine, Hospital for Sick Children Research Institute, Toronto, ON, M5G 0A4, Canada.
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50
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Clements CM, Vögeli B, Shellman YG, Henen MA. SAM1 domain of SASH1 harbors distinctive structural heterogeneity. J Struct Biol 2022; 214:107914. [PMID: 36341956 PMCID: PMC9733425 DOI: 10.1016/j.jsb.2022.107914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 09/28/2022] [Accepted: 10/25/2022] [Indexed: 11/06/2022]
Abstract
The sterile alpha motif (SAM) domains are among the most versatile protein domains in biology, and the variety of the oligomerization states contribute to their diverse roles in many diseases. A better understanding of the structure and dynamics of various SAM domains will provide a scientific basis for drug development targeting them. Here, we used SEC-MALS, HPLC, NMR, and other biophysical techniques to characterize the structural features and dynamics of the SAM1 domain in SASH1. SASH1 is a scaffold protein belonging to the same family as SASH3. Unlike the dimerization seen in SASH3's SAM domain, our SEC-MALS and SE-HPLC showed that SAM1 exists primarily as a less compact monomer with a minor oligomer. NMR assignment, relaxation, and exchange experiments revealed the presence of both a disordered monomer and a more structured oligomer with multiple timescale exchange regimes in solution. Mutagenesis and SE-HPLC showed that D663A/T664K substitutions in SAM1 increased its oligomerization. In sum, this study is the first to characterize a disordered structure for a SAM domain, provides additional evidence and framework for the diversity of SAM domains, and identifies a region in SAM1 as a potential starting point to further characterize the structural mechanism of oligomerization of the domain.
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Affiliation(s)
- Christopher M Clements
- Department of Dermatology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Beat Vögeli
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Yiqun G Shellman
- Department of Dermatology, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Morkos A Henen
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
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