1
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Yi HB, Lee S, Seo K, Kim H, Kim M, Lee HS. Cellular and Biophysical Applications of Genetic Code Expansion. Chem Rev 2024; 124:7465-7530. [PMID: 38753805 DOI: 10.1021/acs.chemrev.4c00112] [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: 05/18/2024]
Abstract
Despite their diverse functions, proteins are inherently constructed from a limited set of building blocks. These compositional constraints pose significant challenges to protein research and its practical applications. Strategically manipulating the cellular protein synthesis system to incorporate novel building blocks has emerged as a critical approach for overcoming these constraints in protein research and application. In the past two decades, the field of genetic code expansion (GCE) has achieved significant advancements, enabling the integration of numerous novel functionalities into proteins across a variety of organisms. This technological evolution has paved the way for the extensive application of genetic code expansion across multiple domains, including protein imaging, the introduction of probes for protein research, analysis of protein-protein interactions, spatiotemporal control of protein function, exploration of proteome changes induced by external stimuli, and the synthesis of proteins endowed with novel functions. In this comprehensive Review, we aim to provide an overview of cellular and biophysical applications that have employed GCE technology over the past two decades.
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Affiliation(s)
- Han Bin Yi
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Seungeun Lee
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Kyungdeok Seo
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Hyeongjo Kim
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Minah Kim
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
| | - Hyun Soo Lee
- Department of Chemistry, Sogang University, 35 Baekbeom-ro, Mapo-gu, Seoul 04107, Republic of Korea
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2
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Qianzhu H, Abdelkader EH, Otting G, Huber T. Genetic Encoding of Fluoro-l-tryptophans for Site-Specific Detection of Conformational Heterogeneity in Proteins by NMR Spectroscopy. J Am Chem Soc 2024; 146:13641-13650. [PMID: 38687675 DOI: 10.1021/jacs.4c03743] [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: 05/02/2024]
Abstract
The substitution of a single hydrogen atom in a protein by fluorine yields a site-specific probe for sensitive detection by 19F nuclear magnetic resonance (NMR) spectroscopy, where the absence of background signal from the protein facilitates the detection of minor conformational species. We developed genetic encoding systems for the site-selective incorporation of 4-fluorotryptophan, 5-fluorotryptophan, 6-fluorotryptophan, and 7-fluorotryptophan in response to an amber stop codon and used them to investigate conformational heterogeneity in a designed amino acid binding protein and in flaviviral NS2B-NS3 proteases. These proteases have been shown to present variable conformations in X-ray crystal structures, including flips of the indole side chains of tryptophan residues. The 19F NMR spectra of different fluorotryptophan isomers installed at the conserved site of Trp83 indicate that the indole ring flip is common in flaviviral NS2B-NS3 proteases in the apo state and suppressed by an active-site inhibitor.
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Affiliation(s)
- Haocheng Qianzhu
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Elwy H Abdelkader
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Gottfried Otting
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Huber
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
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3
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Ben‐Ishay Y, Barak Y, Feintuch A, Ouari O, Pierro A, Mileo E, Su X, Goldfarb D. Exploring the dynamics and structure of PpiB in living Escherichia coli cells using electron paramagnetic resonance spectroscopy. Protein Sci 2024; 33:e4903. [PMID: 38358137 PMCID: PMC10868451 DOI: 10.1002/pro.4903] [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: 11/14/2023] [Revised: 12/29/2023] [Accepted: 01/04/2024] [Indexed: 02/16/2024]
Abstract
The combined effects of the cellular environment on proteins led to the definition of a fifth level of protein structural organization termed quinary structure. To explore the implication of potential quinary structure for globular proteins, we studied the dynamics and conformations of Escherichia coli (E. coli) peptidyl-prolyl cis/trans isomerase B (PpiB) in E. coli cells. PpiB plays a major role in maturation and regulation of folded proteins by catalyzing the cis/trans isomerization of the proline imidic peptide bond. We applied electron paramagnetic resonance (EPR) techniques, utilizing both Gadolinium (Gd(III)) and nitroxide spin labels. In addition to using standard spin labeling approaches with genetically engineered cysteines, we incorporated an unnatural amino acid to achieve Gd(III)-nitroxide orthogonal labeling. We probed PpiB's residue-specific dynamics by X-band continuous wave EPR at ambient temperatures and its structure by double electron-electron resonance (DEER) on frozen samples. PpiB was delivered to E. coli cells by electroporation. We report a significant decrease in the dynamics induced by the cellular environment for two chosen labeling positions. These changes could not be reproduced by adding crowding agents and cell extracts. Concomitantly, we report a broadening of the distance distribution in E. coli, determined by Gd(III)-Gd(III) DEER measurements, as compared with solution and human HeLa cells. This suggests an increase in the number of PpiB conformations present in E. coli cells, possibly due to interactions with other cell components, which also contributes to the reduction in mobility and suggests the presence of a quinary structure.
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Affiliation(s)
- Yasmin Ben‐Ishay
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovotIsrael
| | - Yoav Barak
- Department of Chemical Research SupportWeizmann Institute of ScienceRehovotIsrael
| | - Akiva Feintuch
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovotIsrael
| | - Olivier Ouari
- CNRS, ICR, Institut de Chimie RadicalaireAix‐Marseille UniversitéMarseilleFrance
| | - Annalisa Pierro
- CNRS, BIP, Laboratoire de Bioénergétique et Ingénierie des ProtéinesAix Marseille UniversitéMarseilleFrance
- Present address:
Konstanz Research School Chemical Biology, Department of ChemistryUniversity of KonstanzKonstanzGermany
| | - Elisabetta Mileo
- CNRS, BIP, Laboratoire de Bioénergétique et Ingénierie des ProtéinesAix Marseille UniversitéMarseilleFrance
| | - Xun‐Cheng Su
- State Key Laboratory of Elemento‐organic Chemistry, Tianjin Key Laboratory of Biosensing and Molecular RecognitionCollege of Chemistry, Nankai UniversityTianjinChina
| | - Daniella Goldfarb
- Department of Chemical and Biological PhysicsWeizmann Institute of ScienceRehovotIsrael
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4
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Ekanayake KB, Mahawaththa MC, Qianzhu H, Abdelkader EH, George J, Ullrich S, Murphy RB, Fry SE, Johansen-Leete J, Payne RJ, Nitsche C, Huber T, Otting G. Probing Ligand Binding Sites on Large Proteins by Nuclear Magnetic Resonance Spectroscopy of Genetically Encoded Non-Canonical Amino Acids. J Med Chem 2023; 66:5289-5304. [PMID: 36920850 DOI: 10.1021/acs.jmedchem.3c00222] [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: 03/16/2023]
Abstract
N6-(((trimethylsilyl)-methoxy)carbonyl)-l-lysine (TMSK) and N6-trifluoroacetyl-l-lysine (TFAK) are non-canonical amino acids, which can be installed in proteins by genetic encoding. In addition, we describe a new aminoacyl-tRNA synthetase specific for N6-(((trimethylsilyl)methyl)-carbamoyl)-l-lysine (TMSNK), which is chemically more stable than TMSK. Using the dimeric SARS-CoV-2 main protease (Mpro) as a model system with three different ligands, we show that the 1H and 19F nuclei of the solvent-exposed trimethylsilyl and CF3 groups produce intense signals in the nuclear magnetic resonance (NMR) spectrum. Their response to active-site ligands differed significantly when positioned near rather than far from the active site. Conversely, the NMR probes failed to confirm the previously reported binding site of the ligand pelitinib, which was found to enhance the activity of Mpro by promoting the formation of the enzymatically active dimer. In summary, the amino acids TMSK, TMSNK, and TFAK open an attractive path for site-specific NMR analysis of ligand binding to large proteins of limited stability and at low concentrations.
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Affiliation(s)
- Kasuni B Ekanayake
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Acton, Canberra, Australian Capital Territory 2601, Australia
| | - Mithun C Mahawaththa
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Acton, Canberra, Australian Capital Territory 2601, Australia
| | - Haocheng Qianzhu
- Research School of Chemistry, Australian National University, Acton, Canberra 2601, Australia
| | - Elwy H Abdelkader
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Acton, Canberra, Australian Capital Territory 2601, Australia
| | - Josemon George
- Research School of Chemistry, Australian National University, Acton, Canberra 2601, Australia
| | - Sven Ullrich
- Research School of Chemistry, Australian National University, Acton, Canberra 2601, Australia
| | - Rhys B Murphy
- Research School of Chemistry, Australian National University, Acton, Canberra 2601, Australia
| | - Sarah E Fry
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Jason Johansen-Leete
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Richard J Payne
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, The University of Sydney, Sydney, New South Wales 2006, Australia
- School of Chemistry, The University of Sydney, Sydney, New South Wales 2006, Australia
| | - Christoph Nitsche
- Research School of Chemistry, Australian National University, Acton, Canberra 2601, Australia
| | - Thomas Huber
- Research School of Chemistry, Australian National University, Acton, Canberra 2601, Australia
| | - Gottfried Otting
- Australian Research Council Centre of Excellence for Innovations in Peptide and Protein Science, Research School of Chemistry, Australian National University, Acton, Canberra, Australian Capital Territory 2601, Australia
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Yanagisawa T, Seki E, Tanabe H, Fujii Y, Sakamoto K, Yokoyama S. Crystal Structure of Pyrrolysyl-tRNA Synthetase from a Methanogenic Archaeon ISO4-G1 and Its Structure-Based Engineering for Highly-Productive Cell-Free Genetic Code Expansion with Non-Canonical Amino Acids. Int J Mol Sci 2023; 24:ijms24076256. [PMID: 37047230 PMCID: PMC10094482 DOI: 10.3390/ijms24076256] [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: 02/22/2023] [Revised: 03/22/2023] [Accepted: 03/24/2023] [Indexed: 03/29/2023] Open
Abstract
Pairs of pyrrolysyl-tRNA synthetase (PylRS) and tRNAPyl from Methanosarcina mazei and Methanosarcina barkeri are widely used for site-specific incorporations of non-canonical amino acids into proteins (genetic code expansion). Previously, we achieved full productivity of cell-free protein synthesis for bulky non-canonical amino acids, including Nε-((((E)-cyclooct-2-en-1-yl)oxy)carbonyl)-L-lysine (TCO*Lys), by using Methanomethylophilus alvus PylRS with structure-based mutations in and around the amino acid binding pocket (first-layer and second-layer mutations, respectively). Recently, the PylRS·tRNAPyl pair from a methanogenic archaeon ISO4-G1 was used for genetic code expansion. In the present study, we determined the crystal structure of the methanogenic archaeon ISO4-G1 PylRS (ISO4-G1 PylRS) and compared it with those of structure-known PylRSs. Based on the ISO4-G1 PylRS structure, we attempted the site-specific incorporation of Nε-(p-ethynylbenzyloxycarbonyl)-L-lysine (pEtZLys) into proteins, but it was much less efficient than that of TCO*Lys with M. alvus PylRS mutants. Thus, the first-layer mutations (Y125A and M128L) of ISO4-G1 PylRS, with no additional second-layer mutations, increased the protein productivity with pEtZLys up to 57 ± 8% of that with TCO*Lys at high enzyme concentrations in the cell-free protein synthesis.
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Affiliation(s)
- Tatsuo Yanagisawa
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan;
- RIKEN Cluster for Science, Technology and Innovation Hub, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan; (E.S.); (H.T.)
- Correspondence: (T.Y.); (S.Y.); Tel.: +81-45-503-9196 (S.Y.)
| | - Eiko Seki
- RIKEN Cluster for Science, Technology and Innovation Hub, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan; (E.S.); (H.T.)
| | - Hiroaki Tanabe
- RIKEN Cluster for Science, Technology and Innovation Hub, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan; (E.S.); (H.T.)
| | - Yoshifumi Fujii
- RIKEN Cluster for Science, Technology and Innovation Hub, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan; (E.S.); (H.T.)
| | - Kensaku Sakamoto
- RIKEN Center for Biosystems Dynamics Research, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan;
| | - Shigeyuki Yokoyama
- RIKEN Cluster for Science, Technology and Innovation Hub, 1-7-22 Suehiro-Cho, Tsurumi, Yokohama 230-0045, Japan; (E.S.); (H.T.)
- Correspondence: (T.Y.); (S.Y.); Tel.: +81-45-503-9196 (S.Y.)
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6
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Update of the Pyrrolysyl-tRNA Synthetase/tRNA Pyl Pair and Derivatives for Genetic Code Expansion. J Bacteriol 2023; 205:e0038522. [PMID: 36695595 PMCID: PMC9945579 DOI: 10.1128/jb.00385-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The cotranslational incorporation of pyrrolysine (Pyl), the 22nd proteinogenic amino acid, into proteins in response to the UAG stop codon represents an outstanding example of natural genetic code expansion. Genetic encoding of Pyl is conducted by the pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA, tRNAPyl. Owing to the high tolerance of PylRS toward diverse amino acid substrates and great orthogonality in various model organisms, the PylRS/tRNAPyl-derived pairs are ideal for genetic code expansion to insert noncanonical amino acids (ncAAs) into proteins of interest. Since the discovery of cellular components involved in the biosynthesis and genetic encoding of Pyl, synthetic biologists have been enthusiastic about engineering PylRS/tRNAPyl-derived pairs to rewrite the genetic code of living cells. Recently, considerable progress has been made in understanding the molecular phylogeny, biochemical properties, and structural features of the PylRS/tRNAPyl pair, guiding its further engineering and optimization. In this review, we cover the basic and updated knowledge of the PylRS/tRNAPyl pair's unique characteristics that make it an outstanding tool for reprogramming the genetic code. In addition, we summarize the recent efforts to create efficient and (mutually) orthogonal PylRS/tRNAPyl-derived pairs for incorporation of diverse ncAAs by genome mining, rational design, and advanced directed evolution methods.
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7
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Choi YN, Cho N, Lee K, Gwon DA, Lee JW, Lee J. Programmable Synthesis of Biobased Materials Using Cell-Free Systems. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2203433. [PMID: 36108274 DOI: 10.1002/adma.202203433] [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: 04/15/2022] [Revised: 08/26/2022] [Indexed: 06/15/2023]
Abstract
Motivated by the intricate mechanisms underlying biomolecule syntheses in cells that chemistry is currently unable to mimic, researchers have harnessed biological systems for manufacturing novel materials. Cell-free systems (CFSs) utilizing the bioactivity of transcriptional and translational machineries in vitro are excellent tools that allow supplementation of exogenous materials for production of innovative materials beyond the capability of natural biological systems. Herein, recent studies that have advanced the ability to expand the scope of biobased materials using CFS are summarized and approaches enabling the production of high-value materials, prototyping of genetic parts and modules, and biofunctionalization are discussed. By extending the reach of chemical and enzymatic reactions complementary to cellular materials, CFSs provide new opportunities at the interface of materials science and synthetic biology.
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Affiliation(s)
- Yun-Nam Choi
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Namjin Cho
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Kanghun Lee
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Da-Ae Gwon
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Jeong Wook Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
| | - Joongoo Lee
- Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
- School of Interdisciplinary Bioscience and Bioengineering (I-Bio), Pohang University of Science and Technology (POSTECH), Pohang, 37673, Republic of Korea
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8
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Theillet FX, Luchinat E. In-cell NMR: Why and how? PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 132-133:1-112. [PMID: 36496255 DOI: 10.1016/j.pnmrs.2022.04.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 06/17/2023]
Abstract
NMR spectroscopy has been applied to cells and tissues analysis since its beginnings, as early as 1950. We have attempted to gather here in a didactic fashion the broad diversity of data and ideas that emerged from NMR investigations on living cells. Covering a large proportion of the periodic table, NMR spectroscopy permits scrutiny of a great variety of atomic nuclei in all living organisms non-invasively. It has thus provided quantitative information on cellular atoms and their chemical environment, dynamics, or interactions. We will show that NMR studies have generated valuable knowledge on a vast array of cellular molecules and events, from water, salts, metabolites, cell walls, proteins, nucleic acids, drugs and drug targets, to pH, redox equilibria and chemical reactions. The characterization of such a multitude of objects at the atomic scale has thus shaped our mental representation of cellular life at multiple levels, together with major techniques like mass-spectrometry or microscopies. NMR studies on cells has accompanied the developments of MRI and metabolomics, and various subfields have flourished, coined with appealing names: fluxomics, foodomics, MRI and MRS (i.e. imaging and localized spectroscopy of living tissues, respectively), whole-cell NMR, on-cell ligand-based NMR, systems NMR, cellular structural biology, in-cell NMR… All these have not grown separately, but rather by reinforcing each other like a braided trunk. Hence, we try here to provide an analytical account of a large ensemble of intricately linked approaches, whose integration has been and will be key to their success. We present extensive overviews, firstly on the various types of information provided by NMR in a cellular environment (the "why", oriented towards a broad readership), and secondly on the employed NMR techniques and setups (the "how", where we discuss the past, current and future methods). Each subsection is constructed as a historical anthology, showing how the intrinsic properties of NMR spectroscopy and its developments structured the accessible knowledge on cellular phenomena. Using this systematic approach, we sought i) to make this review accessible to the broadest audience and ii) to highlight some early techniques that may find renewed interest. Finally, we present a brief discussion on what may be potential and desirable developments in the context of integrative studies in biology.
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Affiliation(s)
- Francois-Xavier Theillet
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
| | - Enrico Luchinat
- Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum - Università di Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; CERM - Magnetic Resonance Center, and Neurofarba Department, Università degli Studi di Firenze, 50019 Sesto Fiorentino, Italy
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9
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Miao Q, Nitsche C, Orton H, Overhand M, Otting G, Ubbink M. Paramagnetic Chemical Probes for Studying Biological Macromolecules. Chem Rev 2022; 122:9571-9642. [PMID: 35084831 PMCID: PMC9136935 DOI: 10.1021/acs.chemrev.1c00708] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Indexed: 12/11/2022]
Abstract
Paramagnetic chemical probes have been used in electron paramagnetic resonance (EPR) and nuclear magnetic resonance (NMR) spectroscopy for more than four decades. Recent years witnessed a great increase in the variety of probes for the study of biological macromolecules (proteins, nucleic acids, and oligosaccharides). This Review aims to provide a comprehensive overview of the existing paramagnetic chemical probes, including chemical synthetic approaches, functional properties, and selected applications. Recent developments have seen, in particular, a rapid expansion of the range of lanthanoid probes with anisotropic magnetic susceptibilities for the generation of structural restraints based on residual dipolar couplings and pseudocontact shifts in solution and solid state NMR spectroscopy, mostly for protein studies. Also many new isotropic paramagnetic probes, suitable for NMR measurements of paramagnetic relaxation enhancements, as well as EPR spectroscopic studies (in particular double resonance techniques) have been developed and employed to investigate biological macromolecules. Notwithstanding the large number of reported probes, only few have found broad application and further development of probes for dedicated applications is foreseen.
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Affiliation(s)
- Qing Miao
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
- School
of Chemistry &Chemical Engineering, Shaanxi University of Science & Technology, Xi’an710021, China
| | - Christoph Nitsche
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Henry Orton
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Mark Overhand
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
| | - Gottfried Otting
- Research
School of Chemistry, The Australian National
University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
- ARC
Centre of Excellence for Innovations in Peptide & Protein Science,
Research School of Chemistry, Australian
National University, Sullivans Creek Road, Canberra, Australian Capital Territory 2601, Australia
| | - Marcellus Ubbink
- Leiden
Institute of Chemistry, Leiden University, Einsteinweg 55, Leiden 2333 CC, The Netherlands
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10
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Abdelkader EH, Qianzhu H, George J, Frkic RL, Jackson CJ, Nitsche C, Otting G, Huber T. Genetic Encoding of Cyanopyridylalanine for In‐Cell Protein Macrocyclization by the Nitrile–Aminothiol Click Reaction. Angew Chem Int Ed Engl 2022; 61:e202114154. [PMID: 35102680 PMCID: PMC9304162 DOI: 10.1002/anie.202114154] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Indexed: 12/04/2022]
Abstract
Cyanopyridylalanines are non‐canonical amino acids that react with aminothiol compounds under physiological conditions in a biocompatible manner without requiring added catalyst. Here we present newly developed aminoacyl‐tRNA synthetases for genetic encoding of meta‐ and para‐cyanopyridylalanine to enable the site‐specific attachment of a wide range of different functionalities. The outstanding utility of the cyanopyridine moiety is demonstrated by examples of i) post‐translational functionalization of proteins, ii) in‐cell macrocyclization of peptides and proteins, and iii) protein stapling. The biocompatible nature of the protein ligation chemistry enabled by the cyanopyridylalanine amino acid opens a new path to specific in vivo protein modifications in complex biological environments.
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Affiliation(s)
- Elwy H. Abdelkader
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Haocheng Qianzhu
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Josemon George
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Rebecca L. Frkic
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Colin J. Jackson
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Christoph Nitsche
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Gottfried Otting
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Thomas Huber
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
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11
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Abdelkader EH, Qianzhu H, George J, Frkic RL, Jackson CJ, Nitsche C, Otting G, Huber T. Genetic Encoding of Cyanopyridylalanine for In‐Cell Protein Macrocyclization by the Nitrile–Aminothiol Click Reaction. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202114154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Elwy H. Abdelkader
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Haocheng Qianzhu
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Josemon George
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Rebecca L. Frkic
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Colin J. Jackson
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Christoph Nitsche
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Gottfried Otting
- ARC Centre of Excellence for Innovations in Peptide & Protein Science Research School of Chemistry Australian National University Canberra ACT 2601 Australia
| | - Thomas Huber
- Research School of Chemistry Australian National University Canberra ACT 2601 Australia
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12
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Qianzhu H, Abdelkader EH, Herath ID, Otting G, Huber T. Site-Specific Incorporation of 7-Fluoro-L-tryptophan into Proteins by Genetic Encoding to Monitor Ligand Binding by 19F NMR Spectroscopy. ACS Sens 2022; 7:44-49. [PMID: 35005899 DOI: 10.1021/acssensors.1c02467] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A mutant aminoacyl-tRNA synthetase identified by a library selection system affords site-specific incorporation of 7-fluoro-L-tryptophan in response to an amber stop codon. The enzyme allows the production of proteins with a single hydrogen atom replaced by a fluorine atom as a sensitive nuclear magnetic resonance (NMR) probe. The substitution of a single hydrogen atom by another element that is as closely similar in size and hydrophobicity as possible minimizes possible perturbations in the structure, stability, and solubility of the protein. The fluorine atom enables site-selective monitoring of the protein response to ligand binding by 19F NMR spectroscopy, as demonstrated with the Zika virus NS2B-NS3 protease.
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Affiliation(s)
- Haocheng Qianzhu
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Elwy H. Abdelkader
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Iresha D. Herath
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Gottfried Otting
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Huber
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
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13
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Sapienza PJ, Currie MM, Lancaster NM, Li K, Aubé J, Goldfarb D, Cloer EW, Major MB, Lee AL. Visualizing an Allosteric Intermediate Using CuAAC Stabilization of an NMR Mixed Labeled Dimer. ACS Chem Biol 2021; 16:2766-2775. [PMID: 34784173 DOI: 10.1021/acschembio.1c00617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Homodimers are the most abundant type of enzyme in cells, and as such, they represent the most elemental system for studying the phenomenon of allostery. In these systems, in which the allosteric features are manifest by the effect of the first binding event on a similar event at the second site, the most informative state is the asymmetric singly bound (lig1) form, yet it tends to be thermodynamically elusive. Here we obtain milligram quantities of lig1 of the allosteric homodimer, chorismate mutase, in the form of a mixed isotopically labeled dimer stabilized by Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) between the subunits. Below, we outline several critical steps required to generate high yields of both types of unnatural amino acid-containing proteins and overcome multiple pitfalls intrinsic to CuAAC to obtain high yields of a highly purified, fully intact, active mixed labeled dimer, which provides the first glimpse of the lig1 intermediate. These data not only will make possible NMR-based investigations of allostery envisioned by us but also should facilitate other structural applications in which specific linkage of proteins is helpful.
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Affiliation(s)
- Paul J. Sapienza
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Michelle M. Currie
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Noah M. Lancaster
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Kelin Li
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Jeffrey Aubé
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
| | - Dennis Goldfarb
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Erica W. Cloer
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Michael B. Major
- Lineberger Comprehensive Cancer Center, The University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, North Carolina 27599, United States
| | - Andrew L. Lee
- Division of Chemical Biology and Medicinal Chemistry, Eshelman School of Pharmacy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, United States
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14
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Wang YH, Jian ML, Chen PJ, Tsou JC, Truong LP, Wang YS. Ferritin Conjugates With Multiple Clickable Amino Acids Encoded by C-Terminal Engineered Pyrrolysyl-tRNA Synthetase. Front Chem 2021; 9:779976. [PMID: 34900939 PMCID: PMC8655692 DOI: 10.3389/fchem.2021.779976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Accepted: 10/20/2021] [Indexed: 11/30/2022] Open
Abstract
This study reports the application of expanding genetic codes in developing protein cage-based delivery systems. The evolved Methanosarcina mazei pyrrolysyl-tRNA synthetase (PylRS)•tRNAPyl pairs derived from directed evolution are examined to probe their recognition for para-substituted phenylalanine analogs. The evolved MmPylRS, AzFRS, harboring a wide range of substrates, is further engineered at the C-terminal region into another variant, AzFRS-MS. AzFRS-MS shows suppression of the elevated sfGFP protein amount up to 10 TAG stop codons when charging p-azido-l-phenylalanine (AzF, 4), which allows the occurrence of click chemistry. Since protein nanocages used as drug delivery systems that encompass multiple drugs through a site-specific loading approach remain largely unexplored, as a proof of concept, the application of AzFRS-MS for the site-specific incorporation of AzF on human heavy chain ferritin (Ftn) is developed. The Ftn-4 conjugate is shown to be able to load multiple fluorescence dyes or a therapeutic agent, doxorubicin (Dox), through the strain-promoted azide-alkyne cycloaddition (SPAAC) click reaction. Aiming to selectively target Her2+ breast cancer cells, Ftn-4-DOX conjugates fused with a HER2 receptor recognition peptide, anti-Her2/neu peptide (AHNP), is developed and demonstrated to be able to deliver Dox into the cell and to prolong the drug release. This work presents another application of evolved MmPylRS systems, whose potential in developing a variety of protein conjugates is noteworthy.
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Affiliation(s)
- Yi-Hui Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Mu-Lung Jian
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Pei-Jung Chen
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Jo-Chu Tsou
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Le P Truong
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
| | - Yane-Shih Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.,Institute of Biochemical Sciences, College of Life Science, National Taiwan University, Taipei, Taiwan
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15
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Orton HW, Qianzhu H, Abdelkader EH, Habel EI, Tan YJ, Frkic RL, Jackson CJ, Huber T, Otting G. Through-Space Scalar 19F- 19F Couplings between Fluorinated Noncanonical Amino Acids for the Detection of Specific Contacts in Proteins. J Am Chem Soc 2021; 143:19587-19598. [PMID: 34780162 DOI: 10.1021/jacs.1c10104] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fluorine atoms are known to display scalar 19F-19F couplings in nuclear magnetic resonance (NMR) spectra when they are sufficiently close in space for nonbonding orbitals to overlap. We show that fluorinated noncanonical amino acids positioned in the hydrophobic core or on the surface of a protein can be linked by scalar through-space 19F-19F (TSJFF) couplings even if the 19F spins are in the time average separated by more than the van der Waals distance. Using two different aromatic amino acids featuring CF3 groups, O-trifluoromethyl-tyrosine and 4-trifluoromethyl-phenylalanine, we show that 19F-19F TOCSY experiments are sufficiently sensitive to detect TSJFF couplings between 2.5 and 5 Hz in the 19 kDa protein PpiB measured on a two-channel 400 MHz NMR spectrometer with a regular room temperature probe. A quantitative J evolution experiment enables the measurement of TSJFF coupling constants that are up to five times smaller than the 19F NMR line width. In addition, a new aminoacyl-tRNA synthetase was identified for genetic encoding of N6-(trifluoroacetyl)-l-lysine (TFA-Lys) and 19F-19F TOCSY peaks were observed between two TFA-Lys residues incorporated into the proteins AncCDT-1 and mRFP despite high solvent exposure and flexibility of the TFA-Lys side chains. With the ready availability of systems for site-specific incorporation of fluorinated amino acids into proteins by genetic encoding, 19F-19F interactions offer a straightforward way to probe the spatial proximity of selected sites without any assignments of 1H NMR resonances.
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Affiliation(s)
- Henry W Orton
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Haocheng Qianzhu
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Elwy H Abdelkader
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Edan I Habel
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Yi Jiun Tan
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Rebecca L Frkic
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Colin J Jackson
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Thomas Huber
- Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
| | - Gottfried Otting
- ARC Centre of Excellence for Innovations in Peptide & Protein Science, Research School of Chemistry, Australian National University, Canberra, ACT 2601, Australia
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16
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Herath ID, Breen C, Hewitt SH, Berki TR, Kassir AF, Dodson C, Judd M, Jabar S, Cox N, Otting G, Butler SJ. A Chiral Lanthanide Tag for Stable and Rigid Attachment to Single Cysteine Residues in Proteins for NMR, EPR and Time-Resolved Luminescence Studies. Chemistry 2021; 27:13009-13023. [PMID: 34152643 PMCID: PMC8518945 DOI: 10.1002/chem.202101143] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Indexed: 12/12/2022]
Abstract
A lanthanide-binding tag site-specifically attached to a protein presents a tool to probe the protein by multiple spectroscopic techniques, including nuclear magnetic resonance, electron paramagnetic resonance and time-resolved luminescence spectroscopy. Here a new stable chiral LnIII tag, referred to as C12, is presented for spontaneous and quantitative reaction with a cysteine residue to generate a stable thioether bond. The synthetic protocol of the tag is relatively straightforward, and the tag is stable for storage and shipping. It displays greatly enhanced reactivity towards selenocysteine, opening a route towards selective tagging of selenocysteine in proteins containing cysteine residues. Loaded with TbIII or TmIII ions, the C12 tag readily generates pseudocontact shifts (PCS) in protein NMR spectra. It produces a relatively rigid tether between lanthanide and protein, which is beneficial for interpretation of the PCSs by single magnetic susceptibility anisotropy tensors, and it is suitable for measuring distance distributions in double electron-electron resonance experiments. Upon reaction with cysteine or other thiol compounds, the TbIII complex exhibits a 100-fold enhancement in luminescence quantum yield, affording a highly sensitive turn-on luminescence probe for time-resolved FRET assays and enzyme reaction monitoring.
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Affiliation(s)
- Iresha D. Herath
- Research School of ChemistryThe Australian National UniversityCanberraACT 2605Australia
| | - Colum Breen
- Department of ChemistryLoughborough UniversityEpinal WayLoughboroughLE11 3TUUK
| | - Sarah H. Hewitt
- Department of ChemistryLoughborough UniversityEpinal WayLoughboroughLE11 3TUUK
| | - Thomas R. Berki
- Department of ChemistryLoughborough UniversityEpinal WayLoughboroughLE11 3TUUK
| | - Ahmad F. Kassir
- Department of ChemistryLoughborough UniversityEpinal WayLoughboroughLE11 3TUUK
| | - Charlotte Dodson
- Department of Pharmacy & PharmacologyUniversity of Bath Claverton DownBathBA2 7AYUK
| | - Martyna Judd
- Research School of ChemistryThe Australian National UniversityCanberraACT 2605Australia
| | - Shereen Jabar
- Research School of ChemistryThe Australian National UniversityCanberraACT 2605Australia
| | - Nicholas Cox
- Research School of ChemistryThe Australian National UniversityCanberraACT 2605Australia
| | - Gottfried Otting
- Research School of ChemistryThe Australian National UniversityCanberraACT 2605Australia
| | - Stephen J. Butler
- Department of ChemistryLoughborough UniversityEpinal WayLoughboroughLE11 3TUUK
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17
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Voleti R, Bali S, Guerrero J, Smothers J, Springhower C, Acosta GA, Brewer KD, Albericio F, Rizo J. Evaluation of the tert-butyl group as a probe for NMR studies of macromolecular complexes. JOURNAL OF BIOMOLECULAR NMR 2021; 75:347-363. [PMID: 34505210 PMCID: PMC9482097 DOI: 10.1007/s10858-021-00380-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Accepted: 08/23/2021] [Indexed: 05/04/2023]
Abstract
The development of methyl transverse relaxation optimized spectroscopy has greatly facilitated the study of macromolecular assemblies by solution NMR spectroscopy. However, limited sample solubility and stability has hindered application of this technique to ongoing studies of complexes formed on membranes by the neuronal SNAREs that mediate neurotransmitter release and synaptotagmin-1, the Ca2+ sensor that triggers release. Since the 1H NMR signal of a tBu group attached to a large protein or complex can be observed with high sensitivity if the group retains high mobility, we have explored the use of this strategy to analyze presynaptic complexes involved in neurotransmitter release. For this purpose, we attached tBu groups at single cysteines of fragments of synaptotagmin-1, complexin-1 and the neuronal SNAREs by reaction with 5-(tert-butyldisulfaneyl)-2-nitrobenzoic acid (BDSNB), tBu iodoacetamide or tBu acrylate. The tBu resonances of the tagged proteins were generally sharp and intense, although tBu groups attached with BDSNB had a tendency to exhibit somewhat broader resonances that likely result because of the shorter linkage between the tBu and the tagged cysteine. Incorporation of the tagged proteins into complexes on nanodiscs led to severe broadening of the tBu resonances in some cases. However, sharp tBu resonances could readily be observed for some complexes of more than 200 kDa at low micromolar concentrations. Our results show that tagging of proteins with tBu groups provides a powerful approach to study large biomolecular assemblies of limited stability and/or solubility that may be applicable even at nanomolar concentrations.
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Affiliation(s)
- Rashmi Voleti
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Sofia Bali
- Center for Alzheimer's and Neurodegenerative Diseases, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jaime Guerrero
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Jared Smothers
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Charis Springhower
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Alicat Scientific, Tucson, AZ, 85743, USA
| | - Gerardo A Acosta
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, and Department of Organic Chemistry, University of Barcelona, 08028, Barcelona, Spain
- Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Spanish National Research Council (CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
| | - Kyle D Brewer
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Fernando Albericio
- CIBER-BBN, Networking Centre on Bioengineering, Biomaterials and Nanomedicine, and Department of Organic Chemistry, University of Barcelona, 08028, Barcelona, Spain
- Institute of Advanced Chemistry of Catalonia (IQAC-CSIC), Spanish National Research Council (CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain
- Peptide Science Laboratory, School of Chemistry and Physics, University of KwaZulu-Natal, Durban, 4001, South Africa
| | - Josep Rizo
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA.
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