1
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Nishimura C, Kikuchi T. Non-Native Structures of Apomyoglobin and Apoleghemoglobin in Folding Intermediates Related to the Protein Misfolding. Molecules 2023; 28:molecules28093970. [PMID: 37175379 PMCID: PMC10179781 DOI: 10.3390/molecules28093970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 04/27/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023] Open
Abstract
Protein folding is essential for a polypeptide chain to acquire its proper structure and function. Globins are a superfamily of ubiquitous heme-binding α-helical proteins whose function is principally to regulate oxygen homoeostasis. In this review, we explore the hierarchical helical formation in the globin proteins apomyoglobin and leghemoglobin, and we discuss the existence of non-native and misfolded structures occurring during the course of folding to its native state. This review summarizes the research aimed at characterizing and comparing the equilibrium and kinetic intermediates, as well as delineating the complete folding pathway at a molecular level, in order to answer the following questions: "What is the mechanism of misfolding via a folding intermediate? Does the non-native structure stabilize the contemporary intermediate structure? Does the non-native structure induce slower folding?" The role of the non-native structures in the folding intermediate related to misfolding is also discussed.
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Affiliation(s)
- Chiaki Nishimura
- Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Tokyo 164-8530, Japan
| | - Takeshi Kikuchi
- Department of Bioinformatics, College of Life Sciences, Ritsumeikan University, Kusatsu 528-8577, Japan
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2
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Chaudhari AS, Chatterjee A, Domingos CAO, Andrikopoulos PC, Liu Y, Andersson I, Schneider B, Lórenz-Fonfría VA, Fuertes G. Genetically encoded non-canonical amino acids reveal asynchronous dark reversion of chromophore, backbone and side-chains in EL222. Protein Sci 2023; 32:e4590. [PMID: 36764820 PMCID: PMC10019195 DOI: 10.1002/pro.4590] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 02/01/2023] [Accepted: 02/06/2023] [Indexed: 02/12/2023]
Abstract
Photoreceptors containing the light-oxygen-voltage (LOV) domain elicit biological responses upon excitation of their flavin mononucleotide (FMN) chromophore by blue light. The mechanism and kinetics of dark-state recovery are not well understood. Here we incorporated the non-canonical amino acid p-cyanophenylalanine (CNF) by genetic code expansion technology at forty-five positions of the bacterial transcription factor EL222. Screening of light-induced changes in infrared (IR) absorption frequency, electric field and hydration of the nitrile groups identified residues CNF31 and CNF35 as reporters of monomer/oligomer and caged/decaged equilibria, respectively. Time-resolved multi-probe UV/Visible and IR spectroscopy experiments of the lit-to-dark transition revealed four dynamical events. Predominantly, rearrangements around the A'α helix interface (CNF31 and CNF35) precede FMN-cysteinyl adduct scission, folding of α-helices (amide bands), and relaxation of residue CNF151. This study illustrates the importance of characterizing all parts of a protein and suggests a key role for the N-terminal A'α extension of the LOV domain in controlling EL222 photocycle length. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Aditya S Chaudhari
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Aditi Chatterjee
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Faculty of Science, Charles University, Prague, Czech Republic
| | - Catarina A O Domingos
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Escola Superior de Tecnologia do Barreiro, Instituto Politécnico de Setúbal, Lavradio, Portugal
| | | | - Yingliang Liu
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
| | - Inger Andersson
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic.,Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
| | | | - Gustavo Fuertes
- Institute of Biotechnology of the Czech Academy of Sciences, Vestec, Czech Republic
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3
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Meinhold DW, Felitsky DJ, Dyson HJ, Wright PE. Transient On- and Off-Pathway Protein Folding Intermediate States Characterized with NMR Relaxation Dispersion. J Phys Chem B 2022; 126:9539-9548. [PMID: 36354189 PMCID: PMC9793904 DOI: 10.1021/acs.jpcb.2c05592] [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: 11/11/2022]
Abstract
The earliest events in the folding of a protein are in general poorly understood. We used NMR R2 relaxation dispersion experiments to study transient local collapse events in the unfolded-state (U) conformational ensemble of apomyoglobin (apoMb). Local residual secondary structure (seen in regions corresponding to the A, D, E, and H helices of the folded protein) is largely unchanged over the pH range of 2.3-2.75, yet a significant pH-dependent increase in the conformational exchange contribution to the R2 relaxation rate (Rex) indicates that transient intramolecular contacts occur on a microsecond to millisecond time scale at pH 2.75. A comparison of 15N and 13CO relaxation dispersion data at pH 2.75 for residues in the A, B, G, and H regions, which participate in the earliest folding intermediates, indicates that chain collapse and secondary structure formation are rapid and concomitant. Increasingly stabilizing conditions (lower temperature, higher pH) result in the observation of a relaxation dispersion in the C, CD, and E regions of the protein, which are known to fold at later stages. Mutation of Trp14 in the A-helix region to Ala eliminates conformational exchange throughout the protein, and the mutation of hydrophobic residues in other regions results in the selective inhibition of conformational exchange in the B, G, or H regions. The R2 dispersion data for WT apoMb at pH 2.75 and 10 °C are best fit to a four-state model ABGH ⇆ AGH ⇆ U ⇆ ABCD that includes on-pathway (AGH and ABGH) and off-pathway (ABCD) transiently folded states, both of which are required to explain the behavior of the mutant proteins. The off-pathway intermediate is destabilized at higher temperatures. Our analysis provides insights into the earliest stages of apoMb folding where the collapsing polypeptide chain samples both productive and nonproductive states with stabilized secondary structure.
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Affiliation(s)
| | | | - H. Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla CA 92037
| | - Peter E. Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla CA 92037
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4
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Mizukami T, Roder H. Advances in Mixer Design and Detection Methods for Kinetics Studies of Macromolecular Folding and Binding on the Microsecond Time Scale. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27113392. [PMID: 35684328 PMCID: PMC9182321 DOI: 10.3390/molecules27113392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/20/2022] [Accepted: 05/21/2022] [Indexed: 11/16/2022]
Abstract
Many important biological processes such as protein folding and ligand binding are too fast to be fully resolved using conventional stopped-flow techniques. Although advances in mixer design and detection methods have provided access to the microsecond time regime, there is room for improvement in terms of temporal resolution and sensitivity. To address this need, we developed a continuous-flow mixing instrument with a dead time of 12 to 27 µs (depending on solution viscosity) and enhanced sensitivity, sufficient for monitoring tryptophan or tyrosine fluorescence changes at fluorophore concentrations as low as 1 µM. Relying on commercially available laser microfabrication services, we obtained an integrated mixer/flow-cell assembly on a quartz chip, based on a cross-channel configuration with channel dimensions and geometry designed to minimize backpressure. By gradually increasing the width of the observation channel downstream from the mixing region, we are able to monitor a reaction progress time window ranging from ~10 µs out to ~3 ms. By combining a solid-state UV laser with a Galvano-mirror scanning strategy, we achieved highly efficient and uniform fluorescence excitation along the flow channel. Examples of applications, including refolding of acid-denatured cytochrome c triggered by a pH jump and binding of a peptide ligand to a PDZ domain, demonstrate the capability of the technique to resolve fluorescence changes down to the 10 µs time regime on modest amounts of reagents.
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5
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Protein folding in vitro and in the cell: From a solitary journey to a team effort. Biophys Chem 2022; 287:106821. [PMID: 35667131 PMCID: PMC9636488 DOI: 10.1016/j.bpc.2022.106821] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 04/18/2022] [Accepted: 04/21/2022] [Indexed: 12/22/2022]
Abstract
Correct protein folding is essential for the health and function of living organisms. Yet, it is not well understood how unfolded proteins reach their native state and avoid aggregation, especially within the cellular milieu. Some proteins, especially small, single-domain and apparent two-state folders, successfully attain their native state upon dilution from denaturant. Yet, many more proteins undergo misfolding and aggregation during this process, in a concentration-dependent fashion. Once formed, native and aggregated states are often kinetically trapped relative to each other. Hence, the early stages of protein life are absolutely critical for proper kinetic channeling to the folded state and for long-term solubility and function. This review summarizes current knowledge on protein folding/aggregation mechanisms in buffered solution and within the bacterial cell, highlighting early stages. Remarkably, teamwork between nascent chain, ribosome, trigger factor and Hsp70 molecular chaperones enables all proteins to overcome aggregation propensities and reach a long-lived bioactive state.
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6
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Abstract
Proteins have dynamic structures that undergo chain motions on time scales spanning from picoseconds to seconds. Resolving the resultant conformational heterogeneity is essential for gaining accurate insight into fundamental mechanistic aspects of the protein folding reaction. The use of high-resolution structural probes, sensitive to population distributions, has begun to enable the resolution of site-specific conformational heterogeneity at different stages of the folding reaction. Different states populated during protein folding, including the unfolded state, collapsed intermediate states, and even the native state, are found to possess significant conformational heterogeneity. Heterogeneity in protein folding and unfolding reactions originates from the reduced cooperativity of various kinds of physicochemical interactions between various structural elements of a protein, and between a protein and solvent. Heterogeneity may arise because of functional or evolutionary constraints. Conformational substates within the unfolded state and the collapsed intermediates that exchange at rates slower than the subsequent folding steps give rise to heterogeneity on the protein folding pathways. Multiple folding pathways are likely to represent distinct sequences of structure formation. Insight into the nature of the energy barriers separating different conformational states populated during (un)folding can also be obtained by resolving heterogeneity.
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Affiliation(s)
- Sandhya Bhatia
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India.,Indian Institute of Science Education and Research, Pune 411008, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India.,Indian Institute of Science Education and Research, Pune 411008, India
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7
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Bhatia S, Krishnamoorthy G, Udgaonkar JB. Resolving Site-Specific Heterogeneity of the Unfolded State under Folding Conditions. J Phys Chem Lett 2021; 12:3295-3302. [PMID: 33764778 DOI: 10.1021/acs.jpclett.1c00098] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Understanding the properties of the unfolded state under folding conditions is of fundamental importance for gaining mechanistic insight into folding as well as misfolding reactions. Toward achieving this objective, the folding reaction of a small protein, monellin, has been resolved structurally and temporally, with the use of the multisite time-resolved FRET methodology. The present study establishes that the initial polypeptide chain collapse is not only heterogeneous but also structurally asymmetric and nonuniform. The population-averaged size for the segments spanning parts of the β-sheet decreases much more than that for the α-helix. Multisite measurements enabled specific and nonspecific components of the initial chain collapse to be discerned. The expanded and compact intermediate subensembles have the properties of a nonspecifically collapsed (hence, random-coil-like) and specifically collapsed (hence, globular) polymer, respectively. During subsequent folding, both the subensembles underwent contraction to varying extents at the four monitored segments, which was close to gradual in nature. The expanded intermediate subensemble exhibited an additional very slow contraction, suggestive of the presence of non-native interactions that result in a higher effective viscosity slowing down intrachain motions under folding conditions.
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Affiliation(s)
- Sandhya Bhatia
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560 065, India
- Indian Institute of Science Education and Research, Pune 411 008, India
| | | | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560 065, India
- Indian Institute of Science Education and Research, Pune 411 008, India
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8
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Akiyama T, Kunishima N, Nemoto S, Kazama K, Hirose M, Sudo Y, Matsuura Y, Naitow H, Murata T. Further thermo-stabilization of thermophilic rhodopsin from Thermus thermophilus JL-18 through engineering in extramembrane regions. Proteins 2020; 89:301-310. [PMID: 33064333 PMCID: PMC7894484 DOI: 10.1002/prot.26015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 09/26/2020] [Accepted: 10/12/2020] [Indexed: 11/11/2022]
Abstract
It is known that a hyperthermostable protein tolerable at temperatures over 100°C can be designed from a soluble globular protein by introducing mutations. To expand the applicability of this technology to membrane proteins, here we report a further thermo-stabilization of the thermophilic rhodopsin from Thermus thermophilus JL-18 as a model membrane protein. Ten single mutations in the extramembrane regions were designed based on a computational prediction of folding free-energy differences upon mutation. Experimental characterizations using the UV-visible spectroscopy and the differential scanning calorimetry revealed that four of ten mutations were thermo-stabilizing: V79K, T114D, A115P, and A116E. The mutation-structure relationship of the TR constructs was analyzed using molecular dynamics simulations at 300 K and at 1800 K that aimed simulating structures in the native and in the random-coil states, respectively. The native-state simulation exhibited an ion-pair formation of the stabilizing V79K mutant as it was designed, and suggested a mutation-induced structural change of the most stabilizing T114D mutant. On the other hand, the random-coil-state simulation revealed a higher structural fluctuation of the destabilizing mutant S8D when compared to the wild type, suggesting that the higher entropy in the random-coil state deteriorated the thermal stability. The present thermo-stabilization design in the extramembrane regions based on the free-energy calculation and the subsequent evaluation by the molecular dynamics may be useful to improve the production of membrane proteins for structural studies.
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Affiliation(s)
- Tomoki Akiyama
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
| | - Naoki Kunishima
- RIKEN RSC-Rigaku Collaboration Center, RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan.,RIKEN SPring-8 Center, Sayo-gun, Hyogo, Japan
| | - Sayaka Nemoto
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
| | - Kazuki Kazama
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
| | - Masako Hirose
- Malvern Panalytical division of Spectris Co., Ltd, Tokyo, Japan
| | - Yuki Sudo
- Division of Pharmaceutical Sciences, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | | | | | - Takeshi Murata
- Department of Chemistry, Graduate School of Science, and Molecular Chirality Research, Chiba University, Chiba, Japan
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9
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Henry L, Panman MR, Isaksson L, Claesson E, Kosheleva I, Henning R, Westenhoff S, Berntsson O. Real-time tracking of protein unfolding with time-resolved x-ray solution scattering. STRUCTURAL DYNAMICS (MELVILLE, N.Y.) 2020; 7:054702. [PMID: 32984436 PMCID: PMC7511240 DOI: 10.1063/4.0000013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2020] [Accepted: 08/17/2020] [Indexed: 05/14/2023]
Abstract
The correct folding of proteins is of paramount importance for their function, and protein misfolding is believed to be the primary cause of a wide range of diseases. Protein folding has been investigated with time-averaged methods and time-resolved spectroscopy, but observing the structural dynamics of the unfolding process in real-time is challenging. Here, we demonstrate an approach to directly reveal the structural changes in the unfolding reaction. We use nano- to millisecond time-resolved x-ray solution scattering to probe the unfolding of apomyoglobin. The unfolding reaction was triggered using a temperature jump, which was induced by a nanosecond laser pulse. We demonstrate a new strategy to interpret time-resolved x-ray solution scattering data, which evaluates ensembles of structures obtained from molecular dynamics simulations. We find that apomyoglobin passes three states when unfolding, which we characterize as native, molten globule, and unfolded. The molten globule dominates the population under the conditions investigated herein, whereas native and unfolded structures primarily contribute before the laser jump and 30 μs after it, respectively. The molten globule retains much of the native structure but shows a dynamic pattern of inter-residue contacts. Our study demonstrates a new strategy to directly observe structural changes over the cause of the unfolding reaction, providing time- and spatially resolved atomic details of the folding mechanism of globular proteins.
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Affiliation(s)
- L. Henry
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - M. R. Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - L. Isaksson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - E. Claesson
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
| | - I. Kosheleva
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, USA
| | - R. Henning
- Center for Advanced Radiation Sources, The University of Chicago, Chicago, Illinois 60637, USA
| | - S. Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, 40530 Gothenburg, Sweden
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10
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Kuwajima K. The Molten Globule, and Two-State vs. Non-Two-State Folding of Globular Proteins. Biomolecules 2020; 10:biom10030407. [PMID: 32155758 PMCID: PMC7175247 DOI: 10.3390/biom10030407] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 03/03/2020] [Accepted: 03/06/2020] [Indexed: 11/16/2022] Open
Abstract
From experimental studies of protein folding, it is now clear that there are two types of folding behavior, i.e., two-state folding and non-two-state folding, and understanding the relationships between these apparently different folding behaviors is essential for fully elucidating the molecular mechanisms of protein folding. This article describes how the presence of the two types of folding behavior has been confirmed experimentally, and discusses the relationships between the two-state and the non-two-state folding reactions, on the basis of available data on the correlations of the folding rate constant with various structure-based properties, which are determined primarily by the backbone topology of proteins. Finally, a two-stage hierarchical model is proposed as a general mechanism of protein folding. In this model, protein folding occurs in a hierarchical manner, reflecting the hierarchy of the native three-dimensional structure, as embodied in the case of non-two-state folding with an accumulation of the molten globule state as a folding intermediate. The two-state folding is thus merely a simplified version of the hierarchical folding caused either by an alteration in the rate-limiting step of folding or by destabilization of the intermediate.
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Affiliation(s)
- Kunihiro Kuwajima
- Department of Physics, School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan; ; Tel.: +81-90-5435-6540
- School of Computational Sciences, Korea Institute for Advanced Study (KIAS), Seoul 02455, Korea
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11
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Begun A, Molochkov A, Niemi AJ. Protein tertiary structure and the myoglobin phase diagram. Sci Rep 2019; 9:10819. [PMID: 31346242 PMCID: PMC6658483 DOI: 10.1038/s41598-019-47317-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 07/11/2019] [Indexed: 02/06/2023] Open
Abstract
We develop an effective theory approach to investigate the phase properties of globular proteins. Instead of interactions between individual atoms or localized interaction centers, the approach builds directly on the tertiary structure of a protein. As an example we construct the phase diagram of (apo)myoglobin with temperature (T) and acidity (pH) as the thermodynamical variables. We describe how myoglobin unfolds from the native folded state to a random coil when temperature and acidity increase. We confirm the presence of two molten globule folding intermediates, and we predict an abrupt transition between the two when acidity changes. When temperature further increases we find that the abrupt transition line between the two molten globule states terminates at a tricritical point, where the helical structures fade away. Our results also suggest that the ligand entry and exit is driven by large scale collective motions that destabilize the myoglobin F-helix.
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Affiliation(s)
- Alexander Begun
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia
| | - Alexander Molochkov
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia
| | - Antti J Niemi
- Laboratory of Physics of Living Matter, Far Eastern Federal University, 690950, Sukhanova 8, Vladivostok, Russia. .,Nordita, Stockholm University, Roslagstullsbacken 23, SE-106 91, Stockholm, Sweden. .,Institut Denis Poisson, CNRS UMR 7013, Parc de Grandmont, F37200, Tours, France. .,Department of Physics, Beijing Institute of Technology, Haidian District, Beijing, 100081, People's Republic of China.
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12
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Monteiro DCF, Vakili M, Harich J, Sztucki M, Meier SM, Horrell S, Josts I, Trebbin M. A microfluidic flow-focusing device for low sample consumption serial synchrotron crystallography experiments in liquid flow. JOURNAL OF SYNCHROTRON RADIATION 2019; 26:406-412. [PMID: 30855249 DOI: 10.1107/s1600577519000304] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2018] [Accepted: 01/07/2019] [Indexed: 06/09/2023]
Abstract
Serial synchrotron crystallography allows low X-ray dose, room-temperature crystal structures of proteins to be determined from a population of microcrystals. Protein production and crystallization is a non-trivial procedure and it is essential to have X-ray-compatible sample environments that keep sample consumption low and the crystals in their native environment. This article presents a fast and optimized manufacturing route to metal-polyimide microfluidic flow-focusing devices which allow for the collection of X-ray diffraction data in flow. The flow-focusing conditions allow for sample consumption to be significantly decreased, while also opening up the possibility of more complex experiments such as rapid mixing for time-resolved serial crystallography. This high-repetition-rate experiment allows for full datasets to be obtained quickly (∼1 h) from crystal slurries in liquid flow. The X-ray compatible microfluidic chips are easily manufacturable, reliable and durable and require sample-flow rates on the order of only 30 µl h-1.
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Affiliation(s)
- Diana C F Monteiro
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Mohammad Vakili
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Jessica Harich
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Michael Sztucki
- ESRF, European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble CS 40220, France
| | - Susanne M Meier
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Sam Horrell
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Inokentijs Josts
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
| | - Martin Trebbin
- The Hamburg Centre for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, Hamburg 22761, Germany
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13
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PFDB: A standardized protein folding database with temperature correction. Sci Rep 2019; 9:1588. [PMID: 30733462 PMCID: PMC6367381 DOI: 10.1038/s41598-018-36992-y] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 11/22/2018] [Indexed: 11/23/2022] Open
Abstract
We constructed a standardized protein folding kinetics database (PFDB) in which the logarithmic rate constants of all listed proteins are calculated at the standard temperature (25 °C). A temperature correction based on the Eyring–Kramers equation was introduced for proteins whose folding kinetics were originally measured at temperatures other than 25 °C. We verified the temperature correction by comparing the logarithmic rate constants predicted and experimentally observed at 25 °C for 14 different proteins, and the results demonstrated improvement of the quality of the database. PFDB consists of 141 (89 two-state and 52 non-two-state) single-domain globular proteins, which has the largest number among the currently available databases of protein folding kinetics. PFDB is thus intended to be used as a standard for developing and testing future predictive and theoretical studies of protein folding. PFDB can be accessed from the following link: http://lee.kias.re.kr/~bala/PFDB.
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14
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Mizukami T, Xu M, Fazlieva R, Bychkova VE, Roder H. Complex Folding Landscape of Apomyoglobin at Acidic pH Revealed by Ultrafast Kinetic Analysis of Core Mutants. J Phys Chem B 2018; 122:11228-11239. [PMID: 30133301 DOI: 10.1021/acs.jpcb.8b06895] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Under mildly acidic conditions (pH 4-4.5) apomyoglobin (apoMb) adopts a partially structured equilibrium state ( M-state) that structurally resembles a kinetic intermediate encountered at a late stage of folding to the native structure at neutral pH. We have previously reported that the M-state is formed rapidly (<1 ms) via a multistate process and thus offers a unique opportunity for exploring early stages of folding by both experimental and computational techniques. In order to gain structural insight into intermediates and barriers at the residue level, we studied the folding/unfolding kinetics of 12 apoMb mutants at pH 4.2 using fluorescence-detected ultrafast mixing techniques. Global analysis of the submillisecond folding/unfolding kinetics vs urea concentration for each variant, based on a sequential four-state mechanism ( U ⇔ I ⇔ L ⇔ M), allowed us to determine elementary rate constants and their dependence on urea concentration for most transitions. Comparison of the free energy diagrams constructed from the kinetic data of the mutants with that of wild-type apoMb yielded quantitative information on the effects of mutations on the free energy (ΔΔ G) of both intermediates and the first two kinetic barriers encountered during folding. Truncation of conserved aliphatic side chains on helices A, G, and H gives rise to a stepwise increase in ΔΔ G as the protein advances from U toward M, consistent with progressive stabilization of native-like contacts within the primary core of apoMb. Helix-helix contacts in the primary core contribute little to the first folding barrier ( U ⇔ I) and thus are not required for folding initiation but are critical for the stability of the late intermediate, L, and the M-state. Alanine substitution of hydrophobic residues at more peripheral helix-helix contact sites of the native structure, which are still absent or unstable in the M-state, shows both positive (destabilizing) and negative (stabilizing) ΔΔ G, indicating that non-native contacts are formed initially and weakened or lost as a result of subsequent structural rearrangement steps.
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Affiliation(s)
- Takuya Mizukami
- Molecular Therapeutics Program , Fox Chase Cancer Center , Philadelphia , Pennsylvania 19111 , United States
| | - Ming Xu
- Molecular Therapeutics Program , Fox Chase Cancer Center , Philadelphia , Pennsylvania 19111 , United States
| | - Ruzaliya Fazlieva
- Molecular Therapeutics Program , Fox Chase Cancer Center , Philadelphia , Pennsylvania 19111 , United States
| | - Valentina E Bychkova
- Laboratory of Protein Physics , Institute of Protein Science, Russian Academy of Sciences , Pushchino , Moscow Region 142290 , Russia
| | - Heinrich Roder
- Molecular Therapeutics Program , Fox Chase Cancer Center , Philadelphia , Pennsylvania 19111 , United States
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Varela AE, Lang JF, Wu Y, Dalphin MD, Stangl AJ, Okuno Y, Cavagnero S. Kinetic Trapping of Folded Proteins Relative to Aggregates under Physiologically Relevant Conditions. J Phys Chem B 2018; 122:7682-7698. [DOI: 10.1021/acs.jpcb.8b05360] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Angela E. Varela
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Jonathan F. Lang
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Yufan Wu
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Matthew D. Dalphin
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Andrew J. Stangl
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Yusuke Okuno
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
| | - Silvia Cavagnero
- Department of Chemistry, University of Wisconsin, 1101 University Avenue, Madison, Wisconsin 53706, United States
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Bychkova VE, Semisotnov GV, Balobanov VA, Finkelstein AV. The Molten Globule Concept: 45 Years Later. BIOCHEMISTRY (MOSCOW) 2018; 83:S33-S47. [DOI: 10.1134/s0006297918140043] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Denz M, Brehm G, Hémonnot CYJ, Spears H, Wittmeier A, Cassini C, Saldanha O, Perego E, Diaz A, Burghammer M, Köster S. Cyclic olefin copolymer as an X-ray compatible material for microfluidic devices. LAB ON A CHIP 2017; 18:171-178. [PMID: 29210424 DOI: 10.1039/c7lc00824d] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The combination of microfluidics and X-ray methods attracts a lot of attention from researchers as it brings together the high controllability of microfluidic sample environments and the small length scales probed by X-rays. In particular, the fields of biophysics and biology have benefited enormously from such approaches. We introduce a straightforward fabrication method for X-ray compatible microfluidic devices made solely from cyclic olefin copolymers. We benchmark the performance of the devices against other devices including more commonly used Kapton windows and obtain data of equal quality using small angle X-ray scattering. An advantage of the devices presented here is that no gluing between interfaces is necessary, rendering the production very reliable. As a biophysical application, we investigate the early time points of the assembly of vimentin intermediate filament proteins into higher-order structures. This weakly scattering protein system leads to high quality data in the new devices, thus opening up the way for numerous future applications.
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Affiliation(s)
- Manuela Denz
- Institute for X-Ray Physics, University of Goettingen, 37077 Göttingen, Germany.
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18
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Abstract
Although each type of protein fold and in some cases individual proteins within a fold classification can have very different mechanisms of folding, the underlying biophysical and biochemical principles that operate to cause a linear polypeptide chain to fold into a globular structure must be the same. In an aqueous solution, the protein takes up the thermodynamically most stable structure, but the pathway along which the polypeptide proceeds in order to reach that structure is a function of the amino acid sequence, which must be the final determining factor, not only in shaping the final folded structure, but in dictating the folding pathway. A number of groups have focused on a single protein or group of proteins, to determine in detail the factors that influence the rate and mechanism of folding in a defined system, with the hope that hypothesis-driven experiments can elucidate the underlying principles governing the folding process. Our research group has focused on the folding of the globin family of proteins, and in particular on the monomeric protein apomyoglobin. Apomyoglobin (apoMb) folds relatively slowly (∼2 s) via an ensemble of obligatory intermediates that form rapidly after the initiation of folding. The folding pathway can be dissected using rapid-mixing techniques, which can probe processes in the millisecond time range. Stopped-flow measurements detected by circular dichroism (CD) or fluorescence spectroscopy give information on the rates of folding events. Quench-flow experiments utilize the differential rates of hydrogen-deuterium exchange of amide protons protected in parts of the structure that are folded early; protection of amides can be detected by mass spectrometry or proton nuclear magnetic resonance spectroscopy (NMR). In addition, apoMb forms an intermediate at equilibrium at pH ∼ 4, which is sufficiently stable for it to be structurally characterized by solution methods such as CD, fluorescence and NMR spectroscopies, and the conformational ensembles formed in the presence of denaturing agents and low pH can be characterized as models for the unfolded states of the protein. Newer NMR techniques such as measurement of residual dipolar couplings in the various partly folded states, and relaxation dispersion measurements to probe invisible states present at low concentrations, have contributed to providing a detailed picture of the apomyoglobin folding pathway. The research summarized in this Account was aimed at characterizing and comparing the equilibrium and kinetic intermediates both structurally and dynamically, as well as delineating the complete folding pathway at a residue-specific level, in order to answer the question: "What is it about the amino acid sequence that causes each molecule in the unfolded protein ensemble to start folding, and, once started, to proceed towards the formation of the correctly folded three-dimensional structure?"
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Affiliation(s)
- H Jane Dyson
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla California 92037, United States
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla California 92037, United States
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NISHIMURA C. Folding of apomyoglobin: Analysis of transient intermediate structure during refolding using quick hydrogen deuterium exchange and NMR. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2017; 93:10-27. [PMID: 28077807 PMCID: PMC5406622 DOI: 10.2183/pjab.93.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 10/31/2016] [Indexed: 05/27/2023]
Abstract
The structures of apomyoglobin folding intermediates have been widely analyzed using physical chemistry methods including fluorescence, circular dichroism, small angle X-ray scattering, NMR, mass spectrometry, and rapid mixing. So far, at least two intermediates (on sub-millisecond- and millisecond-scales) have been demonstrated for apomyoglobin folding. The combination of pH-pulse labeling and NMR is a useful tool for analyzing the kinetic intermediates at the atomic level. Its use has revealed that the latter-phase kinetic intermediate of apomyoglobin (6 ms) was composed of helices A, B, G and H, whereas the equilibrium intermediate, called the pH 4 molten-globule intermediate, was composed mainly of helices A, G and H. The improved strategy for the analysis of the kinetic intermediate was developed to include (1) the dimethyl sulfoxide method, (2) data processing with the various labeling times, and (3) a new in-house mixer. Particularly, the rapid mixing revealed that helices A and G were significantly more protected at the earlier stage (400 µs) of the intermediate (former-phase intermediate) than the other helices. Mutation studies, where each hydrophobic residue was replaced with an alanine in helices A, B, E, F, G and H, indicated that both non-native and native-like structures exist in the latter-phase folding intermediate. The N-terminal part of helix B is a weak point in the intermediate, and the docking of helix E residues to the core of the A, B, G and H helices was interrupted by a premature helix B, resulting in the accumulation of the intermediate composed of helices A, B, G and H. The prediction-based protein engineering produced important mutants: Helix F in a P88K/A90L/S92K/A94L mutant folded in the latter-phase intermediate, although helix F in the wild type does not fold even at the native state. Furthermore, in the L11G/W14G/A70L/G73W mutant, helix A did not fold but helix E did, which is similar to what was observed in the kinetic intermediate of apoleghemoglobin. Thus, this protein engineering resulted in a changed structure for the apomyoglobin folding intermediate.
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Affiliation(s)
- Chiaki NISHIMURA
- Faculty of Pharmaceutical Sciences, Teikyo Heisei University, Nakano-ku, Tokyo, Japan
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20
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Peng X, Sieradzan AK, Niemi AJ. Thermal unfolding of myoglobin in the Landau-Ginzburg-Wilson approach. Phys Rev E 2016; 94:062405. [PMID: 28085346 DOI: 10.1103/physreve.94.062405] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2015] [Indexed: 11/07/2022]
Abstract
The Landau-Ginzburg-Wilson paradigm is applied to model the low-temperature crystallographic Cα backbone structure of sperm whale myoglobin. The Glauber protocol is employed to simulate its response to an increase in ambient temperature. The myoglobin is found to unfold from its native state by a succession of α-helical intermediates, fully in line with the observed folding and unfolding patterns in denaturation experiments. In particular, a molten globule intermediate is identified with experimentally correct attributes. A detailed, experimentally testable contact map is constructed to characterize the specifics of the unfolding pathway, including the formation of long-range interactions. The results reveal how the unfolding process of a protein is driven by the interplay between, and a successive melting of, its modular secondary structure components.
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Affiliation(s)
- Xubiao Peng
- Department of Physics and Astronomy, University of British Columbia, Vancouver, British Columbia V6T1Z4, Canada
| | - Adam K Sieradzan
- Faculty of Chemistry, University of Gdansk, Wita Stwosza 63, 80-308 Gdańsk, Poland
| | - Antti J Niemi
- Department of Physics and Astronomy, Uppsala University, P. O. Box 803, S-75108, Uppsala, Sweden.,Laboratoire de Mathematiques et Physique Theorique CNRS UMR 6083, Fédération Denis Poisson, Université de Tours, Parc de Grandmont, F37200, Tours, France.,Department of Physics, Beijing Institute of Technology, Haidian District, Beijing 100081, People's Republic of China
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21
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Ghazal A, Lafleur JP, Mortensen K, Kutter JP, Arleth L, Jensen GV. Recent advances in X-ray compatible microfluidics for applications in soft materials and life sciences. LAB ON A CHIP 2016; 16:4263-4295. [PMID: 27731448 DOI: 10.1039/c6lc00888g] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
The increasingly narrow and brilliant beams at X-ray facilities reduce the requirements for both sample volume and data acquisition time. This creates new possibilities for the types and number of sample conditions that can be examined but simultaneously increases the demands in terms of sample preparation. Microfluidic-based sample preparation techniques have emerged as elegant alternatives that can be integrated directly into the experimental X-ray setup remedying several shortcomings of more traditional methods. We review the use of microfluidic devices in conjunction with X-ray measurements at synchrotron facilities in the context of 1) mapping large parameter spaces, 2) performing time resolved studies of mixing-induced kinetics, and 3) manipulating/processing samples in ways which are more demanding or not accessible on the macroscale. The review covers the past 15 years and focuses on applications where synchrotron data collection is performed in situ, i.e. directly on the microfluidic platform or on a sample jet from the microfluidic device. Considerations such as the choice of materials and microfluidic designs are addressed. The combination of microfluidic devices and measurements at large scale X-ray facilities is still emerging and far from mature, but it definitely offers an exciting array of new possibilities.
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Affiliation(s)
- Aghiad Ghazal
- Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
| | - Josiane P Lafleur
- Dept. of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Kell Mortensen
- Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
| | - Jörg P Kutter
- Dept. of Pharmacy, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Lise Arleth
- Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
| | - Grethe V Jensen
- Niels Bohr Institute, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark.
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22
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Ghazal A, Gontsarik M, Kutter JP, Lafleur JP, Labrador A, Mortensen K, Yaghmur A. Direct monitoring of calcium-triggered phase transitions in cubosomes using small-angle X-ray scattering combined with microfluidics. J Appl Crystallogr 2016. [DOI: 10.1107/s1600576716014199] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
This article introduces a simple microfluidic device that can be combined with synchrotron small-angle X-ray scattering (SAXS) for monitoring dynamic structural transitions. The microfluidic device is a thiol–ene-based system equipped with 125 µm-thick polystyrene windows, which are suitable for X-ray experiments. The device was prepared by soft lithography using elastomeric molds followed by a simple UV-initiated curing step to polymerize the chip material and simultaneously seal the device with the polystyrene windows. The microfluidic device was successfully used to explore the dynamics of the structural transitions of phytantriol/dioleoylphosphatidylglycerol-based cubosomes on exposure to a buffer containing calcium ions. The resulting SAXS data were resolved in the time frame between 0.5 and 5.5 s, and a calcium-triggered structural transition from an internal inverted-type cubic phase of symmetryIm3mto an internal inverted-type cubic phase of symmetryPn3mwas detected. The combination of microfluidics with X-ray techniques opens the door to the investigation of early dynamic structural transitions, which is not possible with conventional techniques such as glass flow cells. The combination of microfluidics with X-ray techniques can be used for investigating protein unfolding, for monitoring the formation of nanoparticles in real time, and for other biomedical and pharmaceutical investigations.
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23
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Mizukami T, Sakuma Y, Maki K. Statistical Mechanical Model for pH-Induced Protein Folding: Application to Apomyoglobin. J Phys Chem B 2016; 120:8970-86. [PMID: 27491483 DOI: 10.1021/acs.jpcb.6b06936] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Despite the major role of pH in protein folding and stability, a quantitative understanding of the pH-induced protein folding mechanism remains elusive. Two conventional models, the Monod-Wyman-Changeux and Linderstrøm-Lang smeared charge models, respectively, have been used to analyze the formation/disruption of specific native structures and fluctuating non-native states. However, there are only a few models that can represent the overall kinetic events of folding/unfolding independent of the properties of relevant molecular species, which has hampered the efforts to systematically analyze pH-induced folding. Here, we constructed a statistical mechanical model that incorporates the protonation mechanism of conventional models along with a combined manual search and least-squares fitting procedure, which was used to investigate the folding of horse apomyoglobin over a wide pH range (2.2-6.7), with a time window ranging from ∼40 μs to ∼100 s, using continuous-/stopped-flow fluorescence at 8 °C. Quantitative analysis assuming a five-state sequential scheme indicated that (1) pH-induced folding/unfolding is represented by both specific binding and Coulombic interactions; (2) kinetic folding/unfolding intermediates share kinetic mechanisms with the equilibrium intermediate, indicating their equivalence; and (3) native-like properties are acquired successively during folding by intermediates and in transition states. This model could also be applied to a variety of association/dissociation processes.
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Affiliation(s)
- Takuya Mizukami
- Graduate School of Science, Nagoya University , Furo-cho, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Yosuke Sakuma
- Graduate School of Science, Nagoya University , Furo-cho, Chikusa, Nagoya, Aichi 464-8602, Japan
| | - Kosuke Maki
- Graduate School of Science, Nagoya University , Furo-cho, Chikusa, Nagoya, Aichi 464-8602, Japan
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24
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Román-Morales E, López-Alfonzo E, Pietri R, López-Garriga J. Sulfmyoglobin Conformational Change: A Role in the Decrease of Oxy-Myoglobin Functionality. Biochem Biophys Rep 2016; 7:386-393. [PMID: 28138567 PMCID: PMC5269605 DOI: 10.1016/j.bbrep.2016.07.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 06/28/2016] [Accepted: 07/01/2016] [Indexed: 12/27/2022] Open
Abstract
This work is focused at understanding the interaction of H2S with Myoglobin (Mb), in particular the Sulfmyoglobin (SMb) product, whose physiological role is controversial and not well understood. The scattering curves, Guinier, Kratky, Porod and P(r) plots were analyzed for oxy-Mb and oxy-Hemoglobin I (oxyHbI) in the absence and presence of H2S, using Small and Wide Angle X-ray Scattering (SAXS/WAXS) technique. Three dimensional models were also generated from the SAXS/WAXS data. The results show that SMb formation, produced by oxyMb and H2S interaction, induces a change in the protein conformation where its envelope has a very small cleft and the protein is more flexible, less rigid and compact. Based on the direct relationship between Mb's structural conformation and its functionality, we suggest that the conformational change observed upon SMb formation plays a contribution to the protein decrease in O2 affinity and, therefore, on its functionality.
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Affiliation(s)
| | | | | | - Juan López-Garriga
- Department of Chemistry, University of Puerto Rico, Mayagüez Campus, PO BOX 9019, Mayagüez, Puerto Rico 00681‐9019
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25
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Seiffert S. Microfluidics and Macromolecules: Top-Down Analytics and Bottom-Up Engineering of Soft Matter at Small Scales. MACROMOL CHEM PHYS 2016. [DOI: 10.1002/macp.201600280] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Sebastian Seiffert
- Johannes Gutenberg-Universität Mainz; Institute of Physical Chemistry; Duesbergweg 10-14 55128 Mainz Germany
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26
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Goluguri RR, Udgaonkar JB. Microsecond Rearrangements of Hydrophobic Clusters in an Initially Collapsed Globule Prime Structure Formation during the Folding of a Small Protein. J Mol Biol 2016; 428:3102-17. [PMID: 27370109 DOI: 10.1016/j.jmb.2016.06.015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Revised: 06/17/2016] [Accepted: 06/19/2016] [Indexed: 12/14/2022]
Abstract
Determining how polypeptide chain collapse initiates structure formation during protein folding is a long standing goal. It has been challenging to characterize experimentally the dynamics of the polypeptide chain, which lead to the formation of a compact kinetic molten globule (MG) in about a millisecond. In this study, the sub-millisecond events that occur early during the folding of monellin from the guanidine hydrochloride-unfolded state have been characterized using multiple fluorescence and fluorescence resonance energy transfer probes. The kinetic MG is shown to form in a noncooperative manner from the unfolded (U) state as a result of at least three different processes happening during the first millisecond of folding. Initial chain compaction completes within the first 37μs, and further compaction occurs only after structure formation commences at a few milliseconds of folding. The transient nonnative and native-like hydrophobic clusters with side chains of certain residues buried form during the initial chain collapse and the nonnative clusters quickly disassemble. Subsequently, partial chain desolvation occurs, leading to the formation of a kinetic MG. The initial chain compaction and subsequent chain rearrangement appear to be barrierless processes. The two structural rearrangements within the collapsed globule appear to prime the protein for the actual folding transition.
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Affiliation(s)
- Rama Reddy Goluguri
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B Udgaonkar
- National Centre for Biological Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India.
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27
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He E, Ren W, Wang J, Li W, Wang W. Effects of heme binding on myoglobin folding: Coarse grained molecular simulations. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2016. [DOI: 10.1142/s0219633615500595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Many proteins contain cofactors, such as heme, ATP and metal ions. Binding of cofactors is not only essential for their biological functions, but also can reshape the intrinsic energy landscape of protein molecules and modulate the folding and stability. However, the molecular mechanism of cofactor coupled protein folding is not well understood. In this work, we study the cofactor coupled folding of myoglobin, which is a typical cofactor (heme) containing protein, by performing molecular dynamics simulations with a structure-based protein model developed based on the energy landscape theory. We showed that the heme binding increases the stability of the myoglobin. More importantly, the heme binding tends to increase the protein folding cooperativity, and switch the folding process from a “three-state” mechanism to a “two-state” mechanism. We also showed that the folding pathways of the myoglobin can be modulated by the heme binding. By performing comparative simulations, we revealed that the above effects of heme binding are resulted from the heme induced folding of F-helix, which is otherwise unstructured at apo state, and the heme mediated contacting interactions around the heme binding site. The simulation results are consistent with available experimental data, and provide insights into the molecular mechanism of the effects of cofactor binding on the protein folding and stability.
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Affiliation(s)
- Erbin He
- National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University Nanjing, 210093, P. R. China
| | - Weitong Ren
- National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University Nanjing, 210093, P. R. China
| | - Jun Wang
- National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University Nanjing, 210093, P. R. China
| | - Wenfei Li
- National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University Nanjing, 210093, P. R. China
| | - Wei Wang
- National Laboratory of Solid State Microstructure and Department of Physics, Nanjing University Nanjing, 210093, P. R. China
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Orevi T, Rahamim G, Amir D, Kathuria S, Bilsel O, Matthews CR, Haas E. Sequential Closure of Loop Structures Forms the Folding Nucleus during the Refolding Transition of the Escherichia coli Adenylate Kinase Molecule. Biochemistry 2015; 55:79-91. [DOI: 10.1021/acs.biochem.5b00849] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Tomer Orevi
- The
Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel 52900
| | - Gil Rahamim
- The
Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel 52900
| | - Dan Amir
- The
Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel 52900
| | - Sagar Kathuria
- Department
of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Osman Bilsel
- Department
of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - C. Robert Matthews
- Department
of Biochemistry and Molecular Pharmacology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, United States
| | - Elisha Haas
- The
Goodman Faculty of Life Sciences, Bar Ilan University, Ramat Gan, Israel 52900
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29
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Where the complex things are: single molecule and ensemble spectroscopic investigations of protein folding dynamics. Curr Opin Struct Biol 2015; 36:1-9. [PMID: 26687767 DOI: 10.1016/j.sbi.2015.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2015] [Accepted: 11/10/2015] [Indexed: 01/11/2023]
Abstract
Progress in our understanding of the simple folding dynamics of small proteins and the complex dynamics of large proteins is reviewed. Recent characterizations of the folding transition path of small proteins revealed a simple dynamics explainable by the native centric model. In contrast, the accumulated data showed the substates containing residual structures in the unfolded state and partially populated intermediates, causing complexity in the early folding dynamics of small proteins. The size of the unfolded proteins in the absence of denaturants is likely expanded but still controversial. The steady progress in the observation of folding of large proteins has clarified the rapid formation of long-range contacts that seem inconsistent with the native centric model, suggesting that the folding strategy of large proteins is distinct from that of small proteins.
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30
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Masbuchin AN, Rohman MS, Putri JF, Cahyaningtyas M, Widodo. 279(Val→Phe) Polymorphism of lipoprotein-associated phospholipase A(2) resulted in changes of folding kinetics and recognition to substrate. Comput Biol Chem 2015; 59 Pt A:199-207. [PMID: 26595893 DOI: 10.1016/j.compbiolchem.2015.10.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 10/12/2015] [Accepted: 10/14/2015] [Indexed: 10/22/2022]
Abstract
INTRODUCTION PLA2G7 encodes Lp-PLA2 having role in the formation of atherosclerotic plaques by catalyzing its substrate, phosphatydilcholine (PC), to be pro-inflammatory substances. The increased risk for coronary artery disease (CAD) in Asian population has been related with this enzyme. 279(Val→Phe) variant was reported to have a protective role against CAD due to, in part, secretion defect or loss of enzymatic function. Therefore, We study folding kinetics and enzyme-substrate interaction in 279(Val→Phe) by using clinical and computational biology approach. METHODS Polymorphisms were detected by genotyping among 103 acute myocardial infarction patients and 37 controls. Folding Lp-PLA2 was simulated using GROMACS software by assessing helicity, hydrogen bond formation and stability. The interactions of Lp-PLA2 and its substrate were simulated using Pyrx software followed by molecular dynamics simulation using YASARA software. RESULT Polymorphism of 279(Val→Phe) was represented by the change of nucleotide from G to T of 994th PLA2G7 gene. The folding simulation suggested a decreased percentage of α-helix, hydrogen bond formation, hydrogen bond stability and hydrophobicity in 279(Val→Phe). The PC did not interact with active site of 279(Val→Phe) as paradoxically observed in 279 valine. 279(Val→Phe) polymorphism is likely to cause unstable binding to the substrate and decrease the enzymatic activity as observed in molecular dynamics simulations. The results of our computational biology study supported a protected effect of 279(Val→Phe) Polymorphism showed by the odd ratio for MI of 0.22 (CI 95% 0.035-1.37) in this study. CONCLUSION 279(Val→Phe) Polymorphism of Lp-PLA2 may lead to decrease the enzymatic activity via changes of folding kinetics and recognition to its substrate.
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Affiliation(s)
- Ainun Nizar Masbuchin
- Department of Biomedical Science, Faculty of Medicine, Brawijaya University, Malang, Indonesia.
| | - Mohammad Saifur Rohman
- Department of Cardiology and Vascular Medicine, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | - Jayarani Fatimah Putri
- Department of Biology, Faculty of Mathematics and Natural Sciences, Brawijaya University, Malang, Indonesia
| | - Miryanti Cahyaningtyas
- Department of Cardiology and Vascular Medicine, Faculty of Medicine, Brawijaya University, Malang, Indonesia
| | - Widodo
- Department of Biology, Faculty of Mathematics and Natural Sciences, Brawijaya University, Malang, Indonesia
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31
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Zerze GH, Best RB, Mittal J. Sequence- and Temperature-Dependent Properties of Unfolded and Disordered Proteins from Atomistic Simulations. J Phys Chem B 2015; 119:14622-30. [PMID: 26498157 DOI: 10.1021/acs.jpcb.5b08619] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We use all-atom molecular simulation with explicit solvent to study the properties of selected intrinsically disordered proteins and unfolded states of foldable proteins, which include chain dimensions and shape, secondary structure propensity, solvent accessible surface area, and contact formation. We find that the qualitative scaling behavior of the chains matches expectations from theory under ambient conditions. In particular, unfolded globular proteins tend to be more collapsed under the same conditions than charged disordered sequences of the same length. However, inclusion of explicit solvent in addition naturally captures temperature-dependent solvation effects, which results in an initial collapse of the chains as temperature is increased, in qualitative agreement with experiment. There is a universal origin to the collapse, revealed in the change of hydration of individual residues as a function of temperature: namely, that the initial collapse is driven by unfavorable solvation free energy of individual residues, which in turn has a strong temperature dependence. We also observe that in unfolded globular proteins, increased temperature also initially favors formation of native-like (rather than non-native-like) structure. Our results help to establish how sequence encodes the degree of intrinsic disorder or order as well as its response to changes in environmental conditions.
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Affiliation(s)
- Gül H Zerze
- Department of Chemical and Biomolecular Engineering, Lehigh University , Bethlehem, Pennsylvania 18015, United States
| | - Robert B Best
- Laboratory of Chemical Physics, NIDDK, National Institutes of Health , Bethesda, Maryland 20892, United States
| | - Jeetain Mittal
- Department of Chemical and Biomolecular Engineering, Lehigh University , Bethlehem, Pennsylvania 18015, United States
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32
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Konuma T, Sakurai K, Yagi M, Goto Y, Fujisawa T, Takahashi S. Highly Collapsed Conformation of the Initial Folding Intermediates of β-Lactoglobulin with Non-Native α-Helix. J Mol Biol 2015; 427:3158-65. [DOI: 10.1016/j.jmb.2015.07.018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Revised: 07/21/2015] [Accepted: 07/22/2015] [Indexed: 10/23/2022]
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33
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Goluguri RR, Udgaonkar JB. Rise of the Helix from a Collapsed Globule during the Folding of Monellin. Biochemistry 2015; 54:5356-65. [DOI: 10.1021/acs.biochem.5b00730] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Affiliation(s)
- Rama Reddy Goluguri
- National Centre for Biological
Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
| | - Jayant B. Udgaonkar
- National Centre for Biological
Sciences, Tata Institute of Fundamental Research, Bengaluru 560065, India
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34
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Mizukami T, Abe Y, Maki K. Evidence for a Shared Mechanism in the Formation of Urea-Induced Kinetic and Equilibrium Intermediates of Horse Apomyoglobin from Ultrarapid Mixing Experiments. PLoS One 2015; 10:e0134238. [PMID: 26244984 PMCID: PMC4526358 DOI: 10.1371/journal.pone.0134238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 07/07/2015] [Indexed: 11/24/2022] Open
Abstract
In this study, the equivalence of the kinetic mechanisms of the formation of urea-induced kinetic folding intermediates and non-native equilibrium states was investigated in apomyoglobin. Despite having similar structural properties, equilibrium and kinetic intermediates accumulate under different conditions and via different mechanisms, and it remains unknown whether their formation involves shared or distinct kinetic mechanisms. To investigate the potential mechanisms of formation, the refolding and unfolding kinetics of horse apomyoglobin were measured by continuous- and stopped-flow fluorescence over a time range from approximately 100 μs to 10 s, along with equilibrium unfolding transitions, as a function of urea concentration at pH 6.0 and 8°C. The formation of a kinetic intermediate was observed over a wider range of urea concentrations (0–2.2 M) than the formation of the native state (0–1.6 M). Additionally, the kinetic intermediate remained populated as the predominant equilibrium state under conditions where the native and unfolded states were unstable (at ~0.7–2 M urea). A continuous shift from the kinetic to the equilibrium intermediate was observed as urea concentrations increased from 0 M to ~2 M, which indicates that these states share a common kinetic folding mechanism. This finding supports the conclusion that these intermediates are equivalent. Our results in turn suggest that the regions of the protein that resist denaturant perturbations form during the earlier stages of folding, which further supports the structural equivalence of transient and equilibrium intermediates. An additional folding intermediate accumulated within ~140 μs of refolding and an unfolding intermediate accumulated in <1 ms of unfolding. Finally, by using quantitative modeling, we showed that a five-state sequential scheme appropriately describes the folding mechanism of horse apomyoglobin.
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Affiliation(s)
- Takuya Mizukami
- Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Yukiko Abe
- Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Kosuke Maki
- Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
- * E-mail:
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35
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Takekiyo T, Yamaguchi E, Yoshida K, Kato M, Yamaguchi T, Yoshimura Y. Interaction Site between the Protein Aggregates and Thiocyanate Ion in Aqueous Solution: A Case Study of 1-Butyl-3-methylimidazolium Thiocyanate. J Phys Chem B 2015; 119:6536-44. [DOI: 10.1021/acs.jpcb.5b01650] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Takahiro Takekiyo
- Department
of Applied Chemistry, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686, Japan
| | - Erika Yamaguchi
- Department
of Applied Chemistry, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686, Japan
| | - Koji Yoshida
- Department
of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka, Fukuoka 814-0810, Japan
| | - Minoru Kato
- Department
of Pharmacy, Ritsumeikan University, 1-1-1 Noji-Higashi, Kusatsu, Shiga 525-8577, Japan
| | - Toshio Yamaguchi
- Department
of Chemistry, Faculty of Science, Fukuoka University, Nanakuma, Jonan-ku, Fukuoka, Fukuoka 814-0810, Japan
| | - Yukihiro Yoshimura
- Department
of Applied Chemistry, National Defense Academy, 1-10-20 Hashirimizu, Yokosuka, Kanagawa 239-8686, Japan
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36
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Mata R, Figueroa M, González-Andrade M, Rivera-Chávez JA, Madariaga-Mazón A, Del Valle P. Calmodulin inhibitors from natural sources: an update. JOURNAL OF NATURAL PRODUCTS 2015; 78:576-586. [PMID: 25536331 DOI: 10.1021/np500954x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Calmodulin (CaM) plays a central role in regulating a myriad of cellular functions in physiological and pathophysiological processes, thus representing an important drug target. In previous reviews, our group has reported relevant information regarding natural anti-CaM compounds up to 2009. Natural sources continue to provide a diverse and unique reservoir of CaM inhibitors for drug and research tool discovery. This review provides an update of natural products with reported CaM inhibitory properties, which includes around 70 natural products and some synthetic analogues, belonging to different structural classes. Most of these natural inhibitors were isolated from fungi and plants and belong to the stilbenoid, polyketide, alkaloid, and peptide structural classes. These products were discovered mainly using a fluorescence-based method on rationally designed biosensors, which are highly specific, low-cost, and selective and have short reaction times. The effect of several antimitotic drugs on Ca(2+)-hCaM is also described.
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Affiliation(s)
- Rachel Mata
- †Facultad de Química and ‡Facultad de Medicina, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | - Mario Figueroa
- †Facultad de Química and ‡Facultad de Medicina, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | - Martín González-Andrade
- †Facultad de Química and ‡Facultad de Medicina, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | - José Alberto Rivera-Chávez
- †Facultad de Química and ‡Facultad de Medicina, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | - Abraham Madariaga-Mazón
- †Facultad de Química and ‡Facultad de Medicina, Universidad Nacional Autónoma de México, México DF 04510, Mexico
| | - Paulina Del Valle
- †Facultad de Química and ‡Facultad de Medicina, Universidad Nacional Autónoma de México, México DF 04510, Mexico
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37
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Ono K, Ito M, Hirota S, Takada S. Dimer domain swapping versus monomer folding in apo-myoglobin studied by molecular simulations. Phys Chem Chem Phys 2015; 17:5006-13. [DOI: 10.1039/c4cp05203j] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Using a coarse-grained symmetrized Go model, we performed a series of folding simulations of two apo-myoglobin molecules restrained at a high density, addressing competition of formation of a domain-swapped dimer with folding to two monomer structures.
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Affiliation(s)
- Koji Ono
- Graduate School of Science
- Kyoto University
- Sakyo Kyoto 606-8502
- Japan
| | - Mashiho Ito
- Graduate School of Science
- Kyoto University
- Sakyo Kyoto 606-8502
- Japan
| | - Shun Hirota
- Graduate School of Materials Science
- Nara Institute of Science and Technology
- Nara 630-0192
- Japan
| | - Shoji Takada
- Graduate School of Science
- Kyoto University
- Sakyo Kyoto 606-8502
- Japan
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38
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Skou M, Skou S, Jensen TG, Vestergaard B, Gillilan RE. In situ microfluidic dialysis for biological small-angle X-ray scattering. J Appl Crystallogr 2014; 47:1355-1366. [PMID: 25242913 DOI: 10.1107/s1600576714012618] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 05/30/2014] [Indexed: 11/10/2022] Open
Abstract
Owing to the demand for low sample consumption and automated sample changing capabilities at synchrotron small-angle X-ray (solution) scattering (SAXS) beamlines, X-ray microfluidics is receiving continuously increasing attention. Here, a remote-controlled microfluidic device is presented for simultaneous SAXS and ultraviolet absorption measurements during protein dialysis, integrated directly on a SAXS beamline. Microfluidic dialysis can be used for monitoring structural changes in response to buffer exchange or, as demonstrated, protein concentration. By collecting X-ray data during the concentration procedure, the risk of inducing protein aggregation due to excessive concentration and storage is eliminated, resulting in reduced sample consumption and improved data quality. The proof of concept demonstrates the effect of halted or continuous flow in the microfluidic device. No sample aggregation was induced by the concentration process at the levels achieved in these experiments. Simulations of fluid dynamics and transport properties within the device strongly suggest that aggregates, and possibly even higher-order oligomers, are preferentially retained by the device, resulting in incidental sample purification. Hence, this versatile microfluidic device enables investigation of experimentally induced structural changes under dynamically controllable sample conditions.
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Affiliation(s)
- Magda Skou
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Søren Skou
- Department of Structural Biophysics, University of Copenhagen, Universitetsparken 6, DK-2100 Copenhagen, Denmark ; MacCHESS (Macromolecular Diffraction Facility at CHESS), Cornell University, Ithaca, NY 14853, USA
| | - Thomas G Jensen
- Department of Micro- and Nanotechnology, The Technical University of Denmark, Ørsteds plads, 2800 Kongens Lyngby, Denmark
| | - Bente Vestergaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, DK-2100 Copenhagen, Denmark
| | - Richard E Gillilan
- MacCHESS (Macromolecular Diffraction Facility at CHESS), Cornell University, Ithaca, NY 14853, USA
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39
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Aoto PC, Nishimura C, Dyson HJ, Wright PE. Probing the non-native H helix translocation in apomyoglobin folding intermediates. Biochemistry 2014; 53:3767-80. [PMID: 24857522 PMCID: PMC4067146 DOI: 10.1021/bi500478m] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
Apomyoglobin folds via sequential
helical intermediates that are
formed by rapid collapse of the A, B, G, and H helix regions. An equilibrium
molten globule with a similar structure is formed near pH 4. Previous
studies suggested that the folding intermediates are kinetically trapped
states in which folding is impeded by non-native packing of the G
and H helices. Fluorescence spectra of mutant proteins in which cysteine
residues were introduced at several positions in the G and H helices
show differential quenching of W14 fluorescence, providing direct
evidence of translocation of the H helix relative to helices A and
G in both the kinetic and equilibrium intermediates. Förster
resonance energy transfer measurements show that a 5-({2-[(acetyl)amino]ethyl}amino)naphthalene-1-sulfonic
acid acceptor coupled to K140C (helix H) is closer to Trp14 (helix
A) in the equilibrium molten globule than in the native state, by
a distance that is consistent with sliding of the H helix in an N-terminal
direction by approximately one helical turn. Formation of an S108C–L135C
disulfide prevents H helix translocation in the equilibrium molten
globule by locking the G and H helices into their native register.
By enforcing nativelike packing of the A, G, and H helices, the disulfide
resolves local energetic frustration and facilitates transient docking
of the E helix region onto the hydrophobic core but has only a small
effect on the refolding rate. The apomyoglobin folding landscape is
highly rugged, with several energetic bottlenecks that frustrate folding;
relief of any one of the major identified bottlenecks is insufficient
to speed progression to the transition state.
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Affiliation(s)
- Phillip C Aoto
- Department of Molecular Biology and Skaggs Institute of Chemical Biology, The Scripps Research Institute , 10550 North Torrey Pines Road, La Jolla, California 92037, United States
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40
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Nakagawa K, Yamada Y, Matsumura Y, Tsukamoto S, Yamamoto-Ohtomo M, Ohtomo H, Okabe T, Fujiwara K, Ikeguchi M. Relationship between chain collapse and secondary structure formation in a partially folded protein. Biopolymers 2014; 101:651-8. [DOI: 10.1002/bip.22433] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2013] [Revised: 08/13/2013] [Accepted: 10/28/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Kanako Nakagawa
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
| | - Yoshiteru Yamada
- Japan Synchrotron Radiation Research Institute; Sayo Hyogo 679-5198 Japan
| | - Yoshitaka Matsumura
- Department of Physics; Kansai Medical University; 18-89 Uyama-Higashi Hirakata 573-1136 Japan
| | - Seiichi Tsukamoto
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
| | - Mio Yamamoto-Ohtomo
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
| | - Hideaki Ohtomo
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
| | - Takahiro Okabe
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
| | - Kazuo Fujiwara
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
| | - Masamichi Ikeguchi
- Department of Bioinformatics; Soka University; 1-236 Tangi-cho Hachioji Tokyo 192-8577 Japan
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41
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Fazelinia H, Xu M, Cheng H, Roder H. Ultrafast hydrogen exchange reveals specific structural events during the initial stages of folding of cytochrome c. J Am Chem Soc 2013; 136:733-40. [PMID: 24364692 DOI: 10.1021/ja410437d] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
Many proteins undergo a sharp decrease in chain dimensions during early stages of folding, prior to the rate-limiting step in folding. However, it remains unclear whether compact states are the result of specific folding events or a general hydrophobic collapse of the poly peptide chain driven by the change in solvent conditions. To address this fundamental question, we extended the temporal resolution of NMR-detected H/D exchange labeling experiments into the microsecond regime by adopting a microfluidics approach. By observing the competition between H/D exchange and folding as a function of labeling pH, coupled with direct measurement of exchange rates in the unfolded state, we were able to monitor hydrogen-bond formation for over 50 individual backbone NH groups within the initial 140 microseconds of folding of horse cytochrome c. Clusters of solvent-shielded amide protons were observed in two α-helical segments in the C-terminal half of the protein, while the N-terminal helix remained largely unstructured, suggesting that proximity in the primary structure is a major factor in promoting helix formation and association at early stages of folding, while the entropically more costly long-range contacts between the N- and C-terminal helices are established only during later stages. Our findings clearly indicate that the initial chain condensation in cytochrome c is driven by specific interactions among a subset of α-helical segments rather than a general hydrophobic collapse.
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Affiliation(s)
- Hossein Fazelinia
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, United States
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42
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Silvestre-Ryan J, Bertoncini CW, Fenwick RB, Esteban-Martin S, Salvatella X. Average conformations determined from PRE data provide high-resolution maps of transient tertiary interactions in disordered proteins. Biophys J 2013; 104:1740-51. [PMID: 23601321 DOI: 10.1016/j.bpj.2013.02.019] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/14/2013] [Accepted: 02/08/2013] [Indexed: 10/27/2022] Open
Abstract
In the last decade it has become evident that disordered states of proteins play important physiological and pathological roles and that the transient tertiary interactions often present in these systems can play a role in their biological activity. The structural characterization of such states has so far largely relied on ensemble representations, which in principle account for both their local and global structural features. However, these approaches are inherently of low resolution due to the large number of degrees of freedom of conformational ensembles and to the sparse nature of the experimental data used to determine them. Here, we overcome these limitations by showing that tertiary interactions in disordered states can be mapped at high resolution by fitting paramagnetic relaxation enhancement data to a small number of conformations, which can be as low as one. This result opens up the possibility of determining the topology of cooperatively collapsed and hidden folded states when these are present in the vast conformational landscape accessible to disordered states of proteins. As a first application, we study the long-range tertiary interactions of acid-unfolded apomyoglobin from experimentally measured paramagnetic relaxation enhancement data.
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Affiliation(s)
- Jordi Silvestre-Ryan
- Joint BSC-IRB Research Programme in Computational Biology, Institute for Research in Biomedicine IRB Barcelona, Barcelona, Spain
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43
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Shiu YJ, Su C, Yeh YL, Liang KK, Hayashi M, Mo Y, Yan Y, Lin SH. Experimental and Theoretical Studies of Protein Folding-Unfolding. J CHIN CHEM SOC-TAIP 2013. [DOI: 10.1002/jccs.200400172] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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44
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Burke KS, Parul D, Reddish MJ, Dyer RB. A simple three-dimensional-focusing, continuous-flow mixer for the study of fast protein dynamics. LAB ON A CHIP 2013; 13:2912-21. [PMID: 23760106 PMCID: PMC3733270 DOI: 10.1039/c3lc50497b] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
We present a simple, yet flexible microfluidic mixer with a demonstrated mixing time as short as 80 μs that is widely accessible because it is made of commercially available parts. To simplify the study of fast protein dynamics, we have developed an inexpensive continuous-flow microfluidic mixer, requiring no specialized equipment or techniques. The mixer uses three-dimensional, hydrodynamic focusing of a protein sample stream by a surrounding sheath solution to achieve rapid diffusional mixing between the sample and sheath. Mixing initiates the reaction of interest. Reactions can be spatially observed by fluorescence or absorbance spectroscopy. We characterized the pixel-to-time calibration and diffusional mixing experimentally. We achieved a mixing time as short as 80 μs. We studied the kinetics of horse apomyoglobin (apoMb) unfolding from the intermediate (I) state to its completely unfolded (U) state, induced by a pH jump from the initial pH of 4.5 in the sample stream to a final pH of 2.0 in the sheath solution. The reaction time was probed using the fluorescence of 1-anilinonaphthalene-8-sulfonate (1,8-ANS) bound to the folded protein. We observed unfolding of apoMb within 760 μs, without populating additional intermediate states under these conditions. We also studied the reaction kinetics of the conversion of pyruvate to lactate catalyzed by lactate dehydrogenase using the intrinsic tryptophan emission of the enzyme. We observe sub-millisecond kinetics that we attribute to Michaelis complex formation and loop domain closure. These results demonstrate the utility of the three-dimensional focusing mixer for biophysical studies of protein dynamics.
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Affiliation(s)
- Kelly S. Burke
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91106
| | | | - Michael J. Reddish
- Emory University, 1515 Dickey Drive, Atlanta, GA 30322, United States of America
| | - R. Brian Dyer
- Emory University, 1515 Dickey Drive, Atlanta, GA 30322, United States of America
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45
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Mizukami T, Xu M, Cheng H, Roder H, Maki K. Nonuniform chain collapse during early stages of staphylococcal nuclease folding detected by fluorescence resonance energy transfer and ultrarapid mixing methods. Protein Sci 2013; 22:1336-48. [PMID: 23904284 DOI: 10.1002/pro.2320] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Revised: 07/10/2013] [Accepted: 07/10/2013] [Indexed: 11/07/2022]
Abstract
The development of tertiary structure during folding of staphylococcal nuclease (SNase) was studied by time-resolved fluorescence resonance energy transfer measured using continuous- and stopped-flow techniques. Variants of this two-domain protein containing intradomain and interdomain fluorescence donor/acceptor pairs (Trp and Cys-linked fluorophore or quencher) were prepared to probe the intradomain and interdomain structural evolution accompanying SNase folding. The intra-domain donor/acceptor pairs are within the β-barrel domain (Trp27/Cys64 and Trp27/Cys97) and the interdomain pair is between the α-helical domain and the β-barrel domain (Trp140/Cys64). Time-resolved energy transfer efficiency accompanying folding and unfolding at different urea concentrations was measured over a time range from 30 μs to ≈ 10 s. Information on average donor/acceptor distances at different stages of the folding process was obtained by using a quantitative kinetic modeling approach. The average distance for the donor/acceptor pairs in the β-barrel domain decreases to nearly native values whereas that of the interdomain donor/acceptor pairs remains unchanged in the earliest intermediate (<500 μs of refolding). This indicates a rapid nonuniform collapse resulting in an ensemble of heterogeneous conformations in which the central region of the β-barrel domain is well developed while the C-terminal α-helical domain remains disordered. The distance between Trp140 and Cys64 decreases to native values on the 100-ms time scale, indicating that the α-helical domain docks onto the preformed β-barrel at a late stage of the folding. In addition, the unfolded state is found to be more compact under native conditions, suggesting that changes in solvent conditions may induce a nonspecific hydrophobic collapse.
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Affiliation(s)
- Takuya Mizukami
- Graduate School of Science, Nagoya University, Nagoya, Aichi 464-8602, Japan
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46
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Vahidi S, Stocks BB, Liaghati-Mobarhan Y, Konermann L. Submillisecond protein folding events monitored by rapid mixing and mass spectrometry-based oxidative labeling. Anal Chem 2013; 85:8618-25. [PMID: 23841479 DOI: 10.1021/ac401148z] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Kinetic measurements can provide insights into protein folding mechanisms. However, the initial (submillisecond) stages of folding still represent a formidable analytical challenge. A number of ultrarapid triggering techniques have been available for some time, but coupling of these techniques with detection methods that are capable of providing detailed structural information has proven to be difficult. The current work addresses this issue by combining submillisecond mixing with laser-induced oxidative labeling. Apomyoglobin (aMb) serves as a model system for our measurements. Exposure of the protein to a brief pulse of hydroxyl radical (·OH) at different time points during folding introduces covalent modifications at solvent accessible side chains. The extent of labeling is monitored using mass spectrometry-based peptide mapping, providing spatially resolved measurements of changes in solvent accessibility. The submillisecond mixer used here improves the time resolution by a factor of 50 compared to earlier ·OH labeling experiments from our laboratory. Data obtained in this way indicate that early aMb folding events are driven by both local and sequence-remote docking of hydrophobic side chains. Assembly of a partially formed A(E)G(H) scaffold after 0.2 ms is followed by stepwise consolidation that ultimately yields the native state. Major conformational changes go to completion within 0.1 s. The technique introduced here is capable of providing in-depth structural information on very short time scales that have thus far been dominated by low resolution (global) spectroscopic probes. By employing submillisecond mixing in conjunction with slower mixing techniques, it is possible to observe complete folding pathways, from fractions of a millisecond all the way to minutes.
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Affiliation(s)
- Siavash Vahidi
- Departments of Chemistry and Biochemistry, The University of Western Ontario , London, Ontario, N6A 5B7, Canada
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47
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Misfolding and amyloid aggregation of apomyoglobin. Int J Mol Sci 2013; 14:14287-300. [PMID: 23839096 PMCID: PMC3742244 DOI: 10.3390/ijms140714287] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2013] [Revised: 06/19/2013] [Accepted: 06/20/2013] [Indexed: 01/03/2023] Open
Abstract
Apomyoglobin is an excellent example of a monomeric all α-helical globular protein whose folding pathway has been extensively studied and well characterized. Structural perturbation induced by denaturants or high temperature as well as amino acid substitution have been described to induce misfolding and, in some cases, aggregation. In this article, we review the molecular mechanism of the aggregation process through which a misfolded form of a mutated apomyoglobin aggregates at physiological pH and room temperature forming an amyloid fibril. The results are compared with data showing that either amyloid or aggregate formation occurs under particular denaturing conditions or upon cleavage of the residues corresponding to the C-terminal helix of apomyoglobin. The results are discussed in terms of the sequence regions that are more important than others in determining the amyloid aggregation process.
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Shukla RT, Kumar N, Sasidhar YU. Molecular dynamics simulations of certain mutant peptide models from staphylococcal nuclease reveal that initial hydrophobic collapse associated with turn propensity drives β-hairpin folding. J Pept Sci 2013; 19:516-27. [PMID: 23794524 DOI: 10.1002/psc.2530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2013] [Revised: 05/10/2013] [Accepted: 05/24/2013] [Indexed: 11/09/2022]
Abstract
An important nucleation event during the folding of staphylococcal nuclease involves the formation of a β-hairpin by the sequence (21) DTVKLMYKGQPMTFR(35) . Earlier studies show that the turn sequence 'YKGQP' has an important role in the folding of this β-hairpin. To understand the active or passive nature of the turn sequence 'YKGQP' in the folding of the aforementioned β-hairpin sequence, we studied glycine mutant peptides Ac-(2) DTVKLMYGGQPMTFR(16) -NMe (K9G:15), Ac-(2) DTVKLMYKGGPMTFR(16) -NMe (Q11G:15), Ac-(2) DTVKLMYGGGPMTFR(16) -NMe (K9G/Q11G:15), and Ac-(2) DTVKLMGGGGGMTFR(16) -NMe (penta-G:15) by using molecular dynamics simulations, starting with two different unfolded states, polyproline II and extended conformational forms. Further, 5mer mutant turn peptides Ac-(2) YGGQP(6) -NMe (K3G:5), Ac-(2) YKGGP(6) -NMe (Q5G:5), Ac-(2) YGGGP(6) -NMe (K3G/Q5G:5), and Ac-(2) GGGGG(6) -NMe (penta-G:5) were also studied individually. Our results show that an initial hydrophobic collapse and loop closure occurs in all 15mer mutants, but only K9G:15 mutant forms a stable native-like β-hairpin. In the other 15mer mutants, the hydrophobic collapsed state would not proceed to β-hairpin formation. Of the different simulations performed for the penta-G:15 mutant, in only one simulation a nonnative β-hairpin conformation is sampled with highly flexible loop region ((8) GGGGG(12) ), which has no specific conformational preference as a 5mer. While the sequence 'YGGQP' in the K3G:5 simulation shows relatively higher β-turn propensity, the presence of this sequence in K9G:15 peptide seems to be driving the β-hairpin formation. Thus, these results seem to suggest that for the formation of a stable β-hairpin, the initial hydrophobic collapse is to be assisted by a turn propensity. Initial hydrophobic collapse alone is not sufficient to guide β-hairpin formation.
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Affiliation(s)
- Rashmi Tambe Shukla
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai, 400076, India
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Zhu L, Kurt N, Choi J, Lapidus LJ, Cavagnero S. Sub-millisecond chain collapse of the Escherichia coli globin ApoHmpH. J Phys Chem B 2013; 117:7868-77. [PMID: 23750553 DOI: 10.1021/jp400174e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Myoglobins are ubiquitous proteins that play a seminal role in oxygen storage, transport, and NO metabolism. The folding mechanism of apomyoglobins from different species has been studied to a fair extent over the last two decades. However, integrated investigations of the entire process, including both the early (sub-ms) and late (ms-s) folding stages, have been missing. Here, we study the folding kinetics of the single-Trp Escherichia coli globin apoHmpH via a combination of continuous-flow microfluidic and stopped-flow approaches. A rich series of molecular events emerges, spanning a very wide temporal range covering more than 7 orders of magnitude, from sub-microseconds to tens of seconds. Variations in fluorescence intensity and spectral shifts reveal that the protein region around Trp120 undergoes a fast collapse within the 8 μs mixing time and gradually reaches a native-like conformation with a half-life of 144 μs from refolding initiation. There are no further fluorescence changes beyond ca. 800 μs, and folding proceeds much more slowly, up to 20 s, with acquisition of the missing helicity (ca. 30%), long after consolidation of core compaction. The picture that emerges is a gradual acquisition of native structure on a free-energy landscape with few large barriers. Interestingly, the single tryptophan, which lies within the main folding core of globins, senses some local structural consolidation events after establishment of native-like core polarity (i.e., likely after core dedydration). In all, this work highlights how the main core of the globin fold is capable of becoming fully native efficiently, on the sub-millisecond time scale.
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Affiliation(s)
- Li Zhu
- Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824, USA
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Udgaonkar JB. Polypeptide chain collapse and protein folding. Arch Biochem Biophys 2013; 531:24-33. [DOI: 10.1016/j.abb.2012.10.003] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2012] [Revised: 10/01/2012] [Accepted: 10/08/2012] [Indexed: 12/11/2022]
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