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Furuya T, Nakane D, Kitanishi K, Katsuumi N, Tsaturyan A, Shcherbakov IN, Unno M, Akitsu T. A novel hybrid protein composed of superoxide-dismutase-active Cu(II) complex and lysozyme. Sci Rep 2023; 13:6892. [PMID: 37106030 PMCID: PMC10140267 DOI: 10.1038/s41598-023-33926-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Accepted: 04/20/2023] [Indexed: 04/29/2023] Open
Abstract
A novel hybrid protein composed of a superoxide dismutase-active Cu(II) complex (CuST) and lysozyme (CuST@lysozyme) was prepared. The results of the spectroscopic and electrochemical analyses confirmed that CuST binds to lysozyme. We determined the crystal structure of CuST@lysozyme at 0.92 Å resolution, which revealed that the His15 imidazole group of lysozyme binds to the Cu(II) center of CuST in the equatorial position. In addition, CuST was fixed in position by the weak axial coordination of the Thr89 hydroxyl group and the hydrogen bond between the guanidinium group of the Arg14 residue and the hydroxyl group of CuST. Furthermore, the combination of CuST with lysozyme did not decrease the superoxide dismutase activity of CuST. Based on the spectral, electrochemical, structural studies, and quantum chemical calculations, an O2- disproportionation mechanism catalyzed by CuST@lysozyme is proposed.
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Affiliation(s)
- Tetsundo Furuya
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Daisuke Nakane
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan.
| | - Kenichi Kitanishi
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Natsuki Katsuumi
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan
| | - Arshak Tsaturyan
- Université Jean Monnet Saint-Etienne, CNRS, Institut d Optique Graduate School, Laboratoire Hubert Curien UMR 5516, 42023, Saint-Étienne, France
- Institute of Physical and Organic Chemistry, Southern Federal University, 194/2 Stachka Ave., Rostov-On-Don, 344090, Russia
| | - Igor N Shcherbakov
- Department of Chemistry, Southern Federal University, 7 Zorge Str., Rostov-On-Don, 344090, Russia
| | - Masaki Unno
- Graduate School of Science and Engineering, Ibaraki University, 4-12-1 Nakanarusawa, Hitachi, Ibaraki, 316-8511, Japan
| | - Takashiro Akitsu
- Department of Chemistry, Faculty of Science, Tokyo University of Science, 1-3 Kagurazaka, Shinjuku-ku, Tokyo, 162-8601, Japan.
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2
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de Sá Ribeiro F, Lima LMTR. Linking B-factor and temperature-induced conformational transition. Biophys Chem 2023; 298:107027. [PMID: 37172417 DOI: 10.1016/j.bpc.2023.107027] [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: 03/17/2023] [Revised: 04/20/2023] [Accepted: 04/26/2023] [Indexed: 05/15/2023]
Abstract
The crystallographic B-factor, also called temperature factor or Debye-Waller factor, has long been used as a surrogate for local protein flexibility. However, the use of the absolute B-factor as a probe for protein motion requires reproducible validation against conformational changes against chemical and physical variables. Here we report the investigation of the thermal dependence of the crystallographic B-factor and its correlation with conformational changes of the protein. We obtained the crystal protein structure coordinates and B-factors at high resolution (1.5 Å) over a broad temperature range (100 K to 325 K). The exponential thermal dependence of B-factor as a function of temperature was equal for both the diffraction intensity data (Wilson B-factor) and for all modeled atoms of the system (protein and non-protein atoms), with a thermal diffusion constant of about 0.0045 K-1, similar for all atoms. The extrapolated B-factor at zero Kelvin (or zero-point fluctuation) varies among the atoms, although with no apparent correlation with temperature-dependent protein conformational changes. These data suggest that the thermal vibration of the atom does not necessarily correlate with the conformational dynamics of the protein.
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Affiliation(s)
- Fernando de Sá Ribeiro
- Laboratório de Biotecnologia Farmacêutica (pbiotech), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; Programa de Pós-Graduação em Química Biológica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, 21941-902, Brazil
| | - Luís Maurício T R Lima
- Laboratório de Biotecnologia Farmacêutica (pbiotech), Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; Programa de Pós-Graduação em Ciências Farmacêuticas, Faculdade de Farmácia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-902, Brazil; Instituto Nacional de Metrologia, Tecnologia e Qualidade (INMETRO), Duque de Caxias, RJ 25250-020, Brazil.
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3
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An ensemble reweighting method for combining the information of experiments and simulations. Chem Phys Lett 2021. [DOI: 10.1016/j.cplett.2021.138821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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4
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Lin FY, Huang J, Pandey P, Rupakheti C, Li J, Roux B, MacKerell AD. Further Optimization and Validation of the Classical Drude Polarizable Protein Force Field. J Chem Theory Comput 2020; 16:3221-3239. [PMID: 32282198 PMCID: PMC7306265 DOI: 10.1021/acs.jctc.0c00057] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The CHARMM Drude-2013 polarizable force field (FF) was developed to include the explicit treatment of induced electronic polarizability, resulting in a more accurate description of the electrostatic interactions in molecular dynamics (MD) simulations. While the Drude-2013 protein FF has shown success in improving the folding properties of α-helical peptides and to reproduce experimental observables in simulations up to 1 μs, some limitations were noted regarding the stability of β-sheet structures in simulations longer than 100 ns as well as larger deviations from crystal structures in simulations of a number of proteins compared to the additive CHARMM36 protein FF. The origin of the instability has been identified and appears to be primarily due to overestimated atomic polarizabilities and induced dipole-dipole interactions on the Cβ, Cγ, and Cδ side chain atoms. To resolve this and other issues, a number of aspects of the model were revisited, resulting in Drude-2019 protein FF. Backbone parameters were optimized targeting the conformational properties of the (Ala)5 peptide in solution along with gas phase properties of the alanine dipeptide. Dipeptides that contain N-acetylated and N'-methylamidated termini, excluding Gly, Pro, and Ala, were used as models to optimize the atomic polarizabilities and Thole screening factors on selected Cβ, Cγ, and Cδ carbons by targeting quantum mechanical (QM) dipole moments and molecular polarizabilities. In addition, to obtain better conformational properties, side chain χ1 and χ2 dihedral parameters were optimized targeting QM data for the respective side chain dipeptide conformations as well as Protein Data Bank survey data based on the χ1, χ2 sampling from Hamiltonian replica-exchange MD simulations of (Ala)4-X-(Ala)4 in solution, where X is the amino acid of interest. Further improvements include optimizing nonbonded interactions between charged residues to reproduce QM interaction energies of the charged-protein model compounds and experimental osmotic pressures. Validation of the optimized Drude protein FF includes MD simulations of a collection of peptides and proteins including β-sheet structures, as well as transmembrane ion channels. Results showed that the updated Drude-2019 protein FF yields smaller overall root-mean-square differences of proteins as compared to the additive CHARMM36m and Drude-2013 FFs as well as similar or improved agreement with experimental NMR properties, allowing for long time scale simulation studies of proteins and more complex biomolecular systems in conjunction with the remainder of the Drude polarizable FF.
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Affiliation(s)
- Fang-Yu Lin
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA
| | - Jing Huang
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA
- Westlake University, 18 Shilongshan Road, Hangzhou 310024, Zhejiang, China
| | - Poonam Pandey
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA
| | - Chetan Rupakheti
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Jing Li
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Benoît Roux
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, 60637, USA
| | - Alexander D. MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, MD 21201, USA
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5
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Lin FY, MacKerell AD. Improved Modeling of Cation-π and Anion-Ring Interactions Using the Drude Polarizable Empirical Force Field for Proteins. J Comput Chem 2020; 41:439-448. [PMID: 31518010 PMCID: PMC7322827 DOI: 10.1002/jcc.26067] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2019] [Revised: 07/15/2019] [Accepted: 08/25/2019] [Indexed: 12/22/2022]
Abstract
Cation-π interactions are noncovalent interactions between a π-electron system and a positively charged ion that are regarded as a strong noncovalent interaction and are ubiquitous in biological systems. Similarly, though less studied, anion-ring interactions are present in proteins along with in-plane interactions of anions with aromatic rings. As these interactions are between a polarizing ion and a polarizable π system, the accuracy of the treatment of these interactions in molecular dynamics (MD) simulations using additive force fields (FFs) may be limited. In the present work, to allow for a better description of ion-π interactions in proteins in the Drude-2013 protein polarizable FF, we systematically optimized the parameters for these interactions targeting model compound quantum mechanical (QM) interaction energies with atom pair-specific Lennard-Jones parameters along with virtual particles as selected ring centroids introduced to target the QM interaction energies and geometries. Subsequently, MD simulations were performed on a series of protein structures where ion-π pairs occur to evaluate the optimized parameters in the context of the Drude-2013 FF. The resulting FF leads to a significant improvement in reproducing the ion-π pair distances observed in experimental protein structures, as well as a smaller root-mean-square differences and fluctuations of the overall protein structures from experimental structures. Accordingly, the optimized Drude-2013 protein polarizable FF is suggested for use in MD simulations of proteins where cation-π and anion-ring interactions are critical. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- Fang-Yu Lin
- Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
| | - Alexander D. MacKerell
- Computer-Aided Drug Design Center, Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
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6
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Tian C, Kasavajhala K, Belfon KAA, Raguette L, Huang H, Migues AN, Bickel J, Wang Y, Pincay J, Wu Q, Simmerling C. ff19SB: Amino-Acid-Specific Protein Backbone Parameters Trained against Quantum Mechanics Energy Surfaces in Solution. J Chem Theory Comput 2019; 16:528-552. [PMID: 31714766 DOI: 10.1021/acs.jctc.9b00591] [Citation(s) in RCA: 741] [Impact Index Per Article: 148.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Molecular dynamics (MD) simulations have become increasingly popular in studying the motions and functions of biomolecules. The accuracy of the simulation, however, is highly determined by the molecular mechanics (MM) force field (FF), a set of functions with adjustable parameters to compute the potential energies from atomic positions. However, the overall quality of the FF, such as our previously published ff99SB and ff14SB, can be limited by assumptions that were made years ago. In the updated model presented here (ff19SB), we have significantly improved the backbone profiles for all 20 amino acids. We fit coupled φ/ψ parameters using 2D φ/ψ conformational scans for multiple amino acids, using as reference data the entire 2D quantum mechanics (QM) energy surface. We address the polarization inconsistency during dihedral parameter fitting by using both QM and MM in aqueous solution. Finally, we examine possible dependency of the backbone fitting on side chain rotamer. To extensively validate ff19SB parameters, and to compare to results using other Amber models, we have performed a total of ∼5 ms MD simulations in explicit solvent. Our results show that after amino-acid-specific training against QM data with solvent polarization, ff19SB not only reproduces the differences in amino-acid-specific Protein Data Bank (PDB) Ramachandran maps better but also shows significantly improved capability to differentiate amino-acid-dependent properties such as helical propensities. We also conclude that an inherent underestimation of helicity is present in ff14SB, which is (inexactly) compensated for by an increase in helical content driven by the TIP3P bias toward overly compact structures. In summary, ff19SB, when combined with a more accurate water model such as OPC, should have better predictive power for modeling sequence-specific behavior, protein mutations, and also rational protein design. Of the explicit water models tested here, we recommend use of OPC with ff19SB.
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Affiliation(s)
- Chuan Tian
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Koushik Kasavajhala
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Kellon A A Belfon
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Lauren Raguette
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - He Huang
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Angela N Migues
- Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - John Bickel
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Yuzhang Wang
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Jorge Pincay
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States
| | - Qin Wu
- Center for Functional Nanomaterials , Brookhaven National Laboratory , Upton , New York 11973 , United States
| | - Carlos Simmerling
- Department of Chemistry , Stony Brook University , Stony Brook , New York 11794 , United States.,Laufer Center for Physical and Quantitative Biology , Stony Brook University , Stony Brook , New York 11794 , United States
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7
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Quirnheim Pais D, Rathmann B, Koepke J, Tomova C, Wurzinger P, Thielmann Y. A standardized technique for high-pressure cooling of protein crystals. Acta Crystallogr D Struct Biol 2017; 73:997-1006. [PMID: 29199979 PMCID: PMC6116161 DOI: 10.1107/s2059798317016357] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2017] [Accepted: 11/14/2017] [Indexed: 12/02/2022] Open
Abstract
Cryogenic temperatures slow down secondary radiation damage during data collection from macromolecular crystals. In 1973, cooling at high pressure was identified as a method for cryopreserving crystals in their mother liquor [Thomanek et al. (1973). Acta Cryst. A29, 263-265]. Results from different groups studying different crystal systems indicated that the approach had merit, although difficulties in making the process work have limited its widespread use. Therefore, a simplified and reliable technique has been developed termed high-pressure cooling (HPC). An essential requirement for HPC is to protect crystals in capillaries. These capillaries form part of new sample holders with SPINE standard dimensions. Crystals are harvested with the capillary, cooled at high pressure (220 MPa) and stored in a cryovial. This system also allows the usage of the standard automation at the synchrotron. Crystals of hen egg-white lysozyme and concanavalin A have been successfully cryopreserved and yielded data sets to resolutions of 1.45 and 1.35 Å, respectively. Extensive work has been performed to define the useful working range of HPC in capillaries with 250 µm inner diameter. Three different 96-well crystallization screens that are most frequently used in our crystallization facility were chosen to study the formation of amorphous ice in this cooling setup. More than 89% of the screening solutions were directly suitable for HPC. This achievement represents a drastic improvement for crystals that suffered from cryoprotection or were not previously eligible for cryoprotection.
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Affiliation(s)
- David Quirnheim Pais
- Molecular Membrane Biology, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| | - Barbara Rathmann
- Molecular Membrane Biology, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| | - Juergen Koepke
- Molecular Membrane Biology, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
| | - Cveta Tomova
- Leica Microsystems Vienna, Hernalser Hauptstrasse 219, 1170 Vienna, Austria
| | - Paul Wurzinger
- Leica Microsystems Vienna, Hernalser Hauptstrasse 219, 1170 Vienna, Austria
| | - Yvonne Thielmann
- Molecular Membrane Biology, Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt am Main, Germany
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8
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Song D, Luo R, Chen HF. The IDP-Specific Force Field ff14IDPSFF Improves the Conformer Sampling of Intrinsically Disordered Proteins. J Chem Inf Model 2017; 57:1166-1178. [PMID: 28448138 DOI: 10.1021/acs.jcim.7b00135] [Citation(s) in RCA: 131] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Intrinsically disordered proteins (IDPs) or intrinsically disordered regions do not have a fixed tertiary structure but play key roles in signal regulation, molecule recognition, and drug targeting. However, it is difficult to study the structure and function of IDPs by traditional experimental methods because of their diverse conformations. Limitations of current generic protein force fields and solvent models were reported in the previous simulations of IDPs. We have also explored overcoming these limitations by developing the ff99IDPs and ff14IDPs force fields to correct the dihedral distribution for eight disorder-promoting residues often observed in IDPs and found encouraging improvements. Here we extend our correction of backbone dihedral terms to all 20 naturally occurring amino acids in the IDP-specific force field ff14IDPSFF to further improve the quality of the modeling of IDPs. Extensive tests of seven IDPs and 14 unstructured short peptides show that the simulated Cα chemical shifts obtained with the ff14IDPSFF force field are in quantitative agreement with those from NMR experiments and are more accurate than those obtained with the base generic force field and also our previous ff14IDPs that only corrects the eight disorder-promoting amino acids. The influence of the solvent model was also investigated and found to be less important. Finally, our explicit-solvent MD simulations further show that ff14IDPSFF can still be used to model structural and dynamical properties of two tested folded proteins, with a slightly better agreement in the loop regions for both structural and dynamical properties. These findings confirm that the newly developed IDP-specific force field ff14IDPSFF can improve the conformer sampling of intrinsically disordered proteins.
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Affiliation(s)
- Dong Song
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, National Experimental Teaching Center for Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Shanghai Jiaotong University , Shanghai 200240, China
| | - Ray Luo
- Departments of Molecular Biology and Biochemistry, Chemical Engineering and Materials Science, and Biomedical Engineering, University of California , Irvine, California 92697-3900, United States
| | - Hai-Feng Chen
- State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, National Experimental Teaching Center for Life Sciences and Biotechnology, College of Life Sciences and Biotechnology, Shanghai Jiaotong University , Shanghai 200240, China.,Shanghai Center for Bioinformation Technology , Shanghai 200235, China
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9
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Maier JA, Martinez C, Kasavajhala K, Wickstrom L, Hauser KE, Simmerling C. ff14SB: Improving the Accuracy of Protein Side Chain and Backbone Parameters from ff99SB. J Chem Theory Comput 2015; 11:3696-713. [PMID: 26574453 DOI: 10.1021/acs.jctc.5b00255] [Citation(s) in RCA: 6270] [Impact Index Per Article: 696.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Molecular mechanics is powerful for its speed in atomistic simulations, but an accurate force field is required. The Amber ff99SB force field improved protein secondary structure balance and dynamics from earlier force fields like ff99, but weaknesses in side chain rotamer and backbone secondary structure preferences have been identified. Here, we performed a complete refit of all amino acid side chain dihedral parameters, which had been carried over from ff94. The training set of conformations included multidimensional dihedral scans designed to improve transferability of the parameters. Improvement in all amino acids was obtained as compared to ff99SB. Parameters were also generated for alternate protonation states of ionizable side chains. Average errors in relative energies of pairs of conformations were under 1.0 kcal/mol as compared to QM, reduced 35% from ff99SB. We also took the opportunity to make empirical adjustments to the protein backbone dihedral parameters as compared to ff99SB. Multiple small adjustments of φ and ψ parameters were tested against NMR scalar coupling data and secondary structure content for short peptides. The best results were obtained from a physically motivated adjustment to the φ rotational profile that compensates for lack of ff99SB QM training data in the β-ppII transition region. Together, these backbone and side chain modifications (hereafter called ff14SB) not only better reproduced their benchmarks, but also improved secondary structure content in small peptides and reproduction of NMR χ1 scalar coupling measurements for proteins in solution. We also discuss the Amber ff12SB parameter set, a preliminary version of ff14SB that includes most of its improvements.
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Affiliation(s)
- James A Maier
- Graduate Program in Biochemistry and Structural Biology, ‡Department of Chemistry, and §Laufer Center for Physical and Quantitative Biology, Stony Brook University , Stony Brook, New York 11794, United States
| | - Carmenza Martinez
- Graduate Program in Biochemistry and Structural Biology, ‡Department of Chemistry, and §Laufer Center for Physical and Quantitative Biology, Stony Brook University , Stony Brook, New York 11794, United States
| | - Koushik Kasavajhala
- Graduate Program in Biochemistry and Structural Biology, ‡Department of Chemistry, and §Laufer Center for Physical and Quantitative Biology, Stony Brook University , Stony Brook, New York 11794, United States
| | - Lauren Wickstrom
- Graduate Program in Biochemistry and Structural Biology, ‡Department of Chemistry, and §Laufer Center for Physical and Quantitative Biology, Stony Brook University , Stony Brook, New York 11794, United States
| | - Kevin E Hauser
- Graduate Program in Biochemistry and Structural Biology, ‡Department of Chemistry, and §Laufer Center for Physical and Quantitative Biology, Stony Brook University , Stony Brook, New York 11794, United States
| | - Carlos Simmerling
- Graduate Program in Biochemistry and Structural Biology, ‡Department of Chemistry, and §Laufer Center for Physical and Quantitative Biology, Stony Brook University , Stony Brook, New York 11794, United States
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10
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Ye W, Ji D, Wang W, Luo R, Chen HF. Test and Evaluation of ff99IDPs Force Field for Intrinsically Disordered Proteins. J Chem Inf Model 2015; 55:1021-9. [PMID: 25919886 DOI: 10.1021/acs.jcim.5b00043] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Over 40% of eukaryotic proteomic sequences have been predicted to be intrinsically disordered proteins (IDPs) or intrinsically disordered regions (IDRs) and confirmed to be associated with many diseases. However, widely used force fields cannot well reproduce the conformers of IDPs. Previously the ff99IDPs force field was released to simulate IDPs with CMAP energy corrections for the eight disorder-promoting residues. In order to further confirm the performance of ff99IDPs, three representative IDP systems (arginine-rich HIV-1 Rev, aspartic proteinase inhibitor IA3, and α-synuclein) were used to test and evaluate the simulation results. The results show that for free disordered proteins, the chemical shifts from the ff99IDPs simulations are in quantitative agreement with those from reported NMR measurements and better than those from ff99SBildn. Thus, ff99IDPs can sample more clusters of disordered conformers than ff99SBildn. For structural proteins, both ff99IDPs and ff99SBildn can well reproduce the conformations. In general, ff99IDPs can successfully be used to simulate the conformations of IDPs and IDRs in both bound and free states. However, relative errors could still be found at the boundaries of ordered residues scattered in long disorder-promoting sequences. Therefore, polarizable force fields might be one of the possible ways to further improve the performance on IDPs.
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Affiliation(s)
- Wei Ye
- †State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Dingjue Ji
- †State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Wei Wang
- †State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Ray Luo
- ‡Department of Molecular Biology and Biochemistry, Department of Chemical Engineering and Materials Science, and Department of Biomedical Engineering, University of California, Irvine, California 92697-3900, United States
| | - Hai-Feng Chen
- †State Key Laboratory of Microbial Metabolism, Department of Bioinformatics and Biostatistics, College of Life Sciences and Biotechnology, Shanghai Jiaotong University, 800 Dongchuan Road, Shanghai 200240, China.,§Shanghai Center for Bioinformation Technology, 1278 Keyuan Road, Shanghai 200235, China
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11
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Hopkins CW, Le Grand S, Walker RC, Roitberg AE. Long-Time-Step Molecular Dynamics through Hydrogen Mass Repartitioning. J Chem Theory Comput 2015; 11:1864-74. [PMID: 26574392 DOI: 10.1021/ct5010406] [Citation(s) in RCA: 697] [Impact Index Per Article: 77.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Previous studies have shown that the method of hydrogen mass repartitioning (HMR) is a potentially useful tool for accelerating molecular dynamics (MD) simulations. By repartitioning the mass of heavy atoms into the bonded hydrogen atoms, it is possible to slow the highest-frequency motions of the macromolecule under study, thus allowing the time step of the simulation to be increased by up to a factor of 2. In this communication, we investigate further how this mass repartitioning allows the simulation time step to be increased in a stable fashion without significantly increasing discretization error. To this end, we ran a set of simulations with different time steps and mass distributions on a three-residue peptide to get a comprehensive view of the effect of mass repartitioning and time step increase on a system whose accessible phase space is fully explored in a relatively short amount of time. We next studied a 129-residue protein, hen egg white lysozyme (HEWL), to verify that the observed behavior extends to a larger, more-realistic, system. Results for the protein include structural comparisons from MD trajectories, as well as comparisons of pKa calculations via constant-pH MD. We also calculated a potential of mean force (PMF) of a dihedral rotation for the MTS [(1-oxyl-2,2,5,5-tetramethyl-pyrroline-3-methyl)methanethiosulfonate] spin label via umbrella sampling with a set of regular MD trajectories, as well as a set of mass-repartitioned trajectories with a time step of 4 fs. Since no significant difference in kinetics or thermodynamics is observed by the use of fast HMR trajectories, further evidence is provided that long-time-step HMR MD simulations are a viable tool for accelerating MD simulations for molecules of biochemical interest.
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Affiliation(s)
- Chad W Hopkins
- Department of Physics, Quantum Theory Project, University of Florida , Gainesville, Florida 32611, United States
| | - Scott Le Grand
- Amazon Web Services, 2201 Westlake Ave., Suite 500, Seattle, Washington 98121, United States
| | - Ross C Walker
- San Diego Supercomputer Center & Department of Chemistry and Biochemistry, University of California San Diego , 9500 Gilman Drive, MC0505, La Jolla, California 92093-0505, United States
| | - Adrian E Roitberg
- Department of Chemistry, Quantum Theory Project, University of Florida , Gainesville, Florida 32611, United States
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12
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Shi Y, Xia Z, Zhang J, Best R, Wu C, Ponder JW, Ren P. The Polarizable Atomic Multipole-based AMOEBA Force Field for Proteins. J Chem Theory Comput 2013; 9:4046-4063. [PMID: 24163642 DOI: 10.1021/ct4003702] [Citation(s) in RCA: 437] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Development of the AMOEBA (Atomic Multipole Optimized Energetics for Biomolecular Simulation) force field for proteins is presented. The current version (AMOEBA-2013) utilizes permanent electrostatic multipole moments through the quadrupole at each atom, and explicitly treats polarization effects in various chemical and physical environments. The atomic multipole electrostatic parameters for each amino acid residue type are derived from high-level gas phase quantum mechanical calculations via a consistent and extensible protocol. Molecular polarizability is modeled via a Thole-style damped interactive induction model based upon distributed atomic polarizabilities. Inter- and intramolecular polarization is treated in a consistent fashion via the Thole model. The intramolecular polarization model ensures transferability of electrostatic parameters among different conformations, as demonstrated by the agreement between QM and AMOEBA electrostatic potentials, and dipole moments of dipeptides. The backbone and side chain torsional parameters were determined by comparing to gas-phase QM (RI-TRIM MP2/CBS) conformational energies of dipeptides and to statistical distributions from the Protein Data Bank. Molecular dynamics simulations are reported for short peptides in explicit water to examine their conformational properties in solution. Overall the calculated conformational free energies and J-coupling constants are consistent with PDB statistics and experimental NMR results, respectively. In addition, the experimental crystal structures of a number of proteins are well maintained during molecular dynamics (MD) simulation. While further calculations are necessary to fully validate the force field, initial results suggest the AMOEBA polarizable multipole force field is able to describe the structure and energetics of peptides and proteins, in both gas-phase and solution environments.
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Affiliation(s)
- Yue Shi
- Department of Biomedical Engineering, The University of Texas at Austin, Austin, TX 78712
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13
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Best RB, Zhu X, Shim J, Lopes PEM, Mittal J, Feig M, MacKerell AD. Optimization of the additive CHARMM all-atom protein force field targeting improved sampling of the backbone φ, ψ and side-chain χ(1) and χ(2) dihedral angles. J Chem Theory Comput 2012; 8:3257-3273. [PMID: 23341755 PMCID: PMC3549273 DOI: 10.1021/ct300400x] [Citation(s) in RCA: 3058] [Impact Index Per Article: 254.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
While the quality of the current CHARMM22/CMAP additive force field for proteins has been demonstrated in a large number of applications, limitations in the model with respect to the equilibrium between the sampling of helical and extended conformations in folding simulations have been noted. To overcome this, as well as make other improvements in the model, we present a combination of refinements that should result in enhanced accuracy in simulations of proteins. The common (non Gly, Pro) backbone CMAP potential has been refined against experimental solution NMR data for weakly structured peptides, resulting in a rebalancing of the energies of the α-helix and extended regions of the Ramachandran map, correcting the α-helical bias of CHARMM22/CMAP. The Gly and Pro CMAPs have been refitted to more accurate quantum-mechanical energy surfaces. Side-chain torsion parameters have been optimized by fitting to backbone-dependent quantum-mechanical energy surfaces, followed by additional empirical optimization targeting NMR scalar couplings for unfolded proteins. A comprehensive validation of the revised force field was then performed against data not used to guide parametrization: (i) comparison of simulations of eight proteins in their crystal environments with crystal structures; (ii) comparison with backbone scalar couplings for weakly structured peptides; (iii) comparison with NMR residual dipolar couplings and scalar couplings for both backbone and side-chains in folded proteins; (iv) equilibrium folding of mini-proteins. The results indicate that the revised CHARMM 36 parameters represent an improved model for the modeling and simulation studies of proteins, including studies of protein folding, assembly and functionally relevant conformational changes.
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Affiliation(s)
- Robert B. Best
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge CB2 1EW
| | - Xiao Zhu
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201
| | - Jihyun Shim
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201
| | - Pedro E. M. Lopes
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201
| | - Jeetain Mittal
- Department of Chemical Engineering, Lehigh University, Bethlehem, Pennsylvania
| | - Michael Feig
- Department of Biochemistry and Molecular Biology and Department of Chemistry, Michigan State University, East Lansing, Michigan 48824
| | - Alexander D. MacKerell
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 Penn Street, Baltimore, Maryland 21201
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14
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Kmetko J, Warkentin M, Englich U, Thorne RE. Can radiation damage to protein crystals be reduced using small-molecule compounds? ACTA CRYSTALLOGRAPHICA. SECTION D, BIOLOGICAL CRYSTALLOGRAPHY 2011; 67:881-93. [PMID: 21931220 PMCID: PMC3176623 DOI: 10.1107/s0907444911032835] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2011] [Accepted: 08/12/2011] [Indexed: 11/10/2022]
Abstract
Recent studies have defined a data-collection protocol and a metric that provide a robust measure of global radiation damage to protein crystals. Using this protocol and metric, 19 small-molecule compounds (introduced either by cocrystallization or soaking) were evaluated for their ability to protect lysozyme crystals from radiation damage. The compounds were selected based upon their ability to interact with radiolytic products (e.g. hydrated electrons, hydrogen, hydroxyl and perhydroxyl radicals) and/or their efficacy in protecting biological molecules from radiation damage in dilute aqueous solutions. At room temperature, 12 compounds had no effect and six had a sensitizing effect on global damage. Only one compound, sodium nitrate, appeared to extend crystal lifetimes, but not in all proteins and only by a factor of two or less. No compound provided protection at T=100 K. Scavengers are ineffective in protecting protein crystals from global damage because a large fraction of primary X-ray-induced excitations are generated in and/or directly attack the protein and because the ratio of scavenger molecules to protein molecules is too small to provide appreciable competitive protection. The same reactivity that makes some scavengers effective radioprotectors in protein solutions may explain their sensitizing effect in the protein-dense environment of a crystal. A more productive focus for future efforts may be to identify and eliminate sensitizing compounds from crystallization solutions.
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Affiliation(s)
- Jan Kmetko
- Physics Department, Kenyon College, Gambier, OH 43022, USA
| | | | - Ulrich Englich
- Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853, USA
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15
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Basso S, Besnard C, Wright JP, Margiolaki I, Fitch A, Pattison P, Schiltz M. Features of the secondary structure of a protein molecule from powder diffraction data. ACTA CRYSTALLOGRAPHICA SECTION D: BIOLOGICAL CRYSTALLOGRAPHY 2010; 66:756-61. [DOI: 10.1107/s0907444910010723] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2009] [Accepted: 03/22/2010] [Indexed: 11/10/2022]
Abstract
Protein powder diffraction is shown to be suitable for obtainingde novosolutions to the phase problem at low resolutionviaphasing methods such as the isomorphous replacement method. Two heavy-atom derivatives (a gadolinium derivative and a holmium derivative) of the tetragonal form of hen egg-white lysozyme were crystallized at room temperature. Using synchrotron radiation, high-quality powder patterns were collected in which pH-induced anisotropic lattice-parameter changes were exploited in order to reduce the challenging and powder-specific problem of overlapping reflections. The phasing power of two heavy-atom derivatives in a multiple isomorphous replacement analysis enabled molecular structural information to be obtained up to approximately 5.3 Å resolution. At such a resolution, features of the secondary structure of the lysozyme molecule can be accurately located using programs dedicated to that effect. In addition, the quoted resolution is sufficient to determine the correct hand of the heavy-atom substructure which leads to an electron-density map representing the protein molecule of proper chirality.
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16
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Abstract
Modular proteins such as titin, fibronectin, and cadherin are ubiquitous components of living cells. Often involved in signaling and mechanical processes, their architecture is characterized by domains containing a variable number of heterogeneous "repeats" arranged in series, with either flexible or rigid linker regions that determine their elasticity. Cadherin repeats arranged in series are unique in that linker regions also feature calcium-binding motifs. While it is well known that the extracellular repeats of cadherin proteins mediate cell-cell adhesion in a calcium-dependent manner, the molecular mechanisms behind the influence of calcium in adhesion dynamics and cadherin's mechanical response are not well understood. Here we show, using molecular dynamics simulations, how calcium ions control the structural integrity of cadherin's linker regions, thereby affecting cadherin's equilibrium dynamics, the availability of key residues involved in cell-cell adhesion, and cadherin's mechanical response. The all-atom, multi-nanosecond molecular dynamics simulations involved the entire C-cadherin extracellular domain solvated in water (a 345,000 atom system). Equilibrium simulations show that the extracellular domain maintains its crystal conformation (elongated and slightly curved) when calcium ions are present. In the absence of calcium ions, however, it assumes a disordered conformation. The conserved residue Trp(2), which is thought to insert itself into a hydrophobic pocket of another cadherin molecule (thereby providing the basis for cell-cell adhesion), switches conformation from exposed to intermittently buried upon removal of calcium ions. Furthermore, the overall mechanical response of C-cadherin's extracellular domain is characterized at low force by changes in shape (tertiary structure elasticity), and at high force by unraveling of secondary structure elements (secondary structure elasticity). This mechanical response is modulated by calcium ions at both low and high force, switching from a stiff, rod-like to a soft, spring-like behavior upon removal of ions. The simulations provide an unprecedented molecular view of calcium-mediated allostery in cadherins, also illustrating the general principles of linker-mediated elasticity of modular proteins relevant not only for cell-cell adhesion and sound transduction, but also muscle elasticity.
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17
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Hornak V, Abel R, Okur A, Strockbine B, Roitberg A, Simmerling C. Comparison of multiple Amber force fields and development of improved protein backbone parameters. Proteins 2007; 65:712-25. [PMID: 16981200 PMCID: PMC4805110 DOI: 10.1002/prot.21123] [Citation(s) in RCA: 5373] [Impact Index Per Article: 316.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The ff94 force field that is commonly associated with the Amber simulation package is one of the most widely used parameter sets for biomolecular simulation. After a decade of extensive use and testing, limitations in this force field, such as over-stabilization of alpha-helices, were reported by us and other researchers. This led to a number of attempts to improve these parameters, resulting in a variety of "Amber" force fields and significant difficulty in determining which should be used for a particular application. We show that several of these continue to suffer from inadequate balance between different secondary structure elements. In addition, the approach used in most of these studies neglected to account for the existence in Amber of two sets of backbone phi/psi dihedral terms. This led to parameter sets that provide unreasonable conformational preferences for glycine. We report here an effort to improve the phi/psi dihedral terms in the ff99 energy function. Dihedral term parameters are based on fitting the energies of multiple conformations of glycine and alanine tetrapeptides from high level ab initio quantum mechanical calculations. The new parameters for backbone dihedrals replace those in the existing ff99 force field. This parameter set, which we denote ff99SB, achieves a better balance of secondary structure elements as judged by improved distribution of backbone dihedrals for glycine and alanine with respect to PDB survey data. It also accomplishes improved agreement with published experimental data for conformational preferences of short alanine peptides and better accord with experimental NMR relaxation data of test protein systems.
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Affiliation(s)
- Viktor Hornak
- Center for Structural Biology, Stony Brook University, Stony Brook, NY 11794
| | - Robert Abel
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, FL 32611
| | - Asim Okur
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794
| | - Bentley Strockbine
- Department of Pharmacological Sciences, Stony Brook University, Stony Brook, NY 11794
| | - Adrian Roitberg
- Department of Chemistry and Quantum Theory Project, University of Florida, Gainesville, FL 32611
| | - Carlos Simmerling
- Department of Chemistry, Stony Brook University, Stony Brook, NY 11794
- Center for Structural Biology, Stony Brook University, Stony Brook, NY 11794
- Computational Science Center, Brookhaven National Laboratory, Upton NY11973
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18
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19
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Kamatari YO, Yamada H, Akasaka K, Jones JA, Dobson CM, Smith LJ. Response of native and denatured hen lysozyme to high pressure studied by 15
N/1
H NMR spectroscopy. ACTA ACUST UNITED AC 2003. [DOI: 10.1046/j.1432-1327.2001.02050.x] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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20
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Schiltz M, Fourme R, Prangé T. Use of noble gases xenon and krypton as heavy atoms in protein structure determination. Methods Enzymol 2003; 374:83-119. [PMID: 14696369 DOI: 10.1016/s0076-6879(03)74004-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Marc Schiltz
- LURE (CNRS-CEAMEN), Batiment 209d, Universite Paris XI, 91898 Orsay, France
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21
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Juers DH, Matthews BW. Reversible lattice repacking illustrates the temperature dependence of macromolecular interactions. J Mol Biol 2001; 311:851-62. [PMID: 11518535 DOI: 10.1006/jmbi.2001.4891] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Flash-freezing, which has become routine in macromolecular X-ray crystallography, causes the crystal to contract substantially. In the case of Escherichia coli beta-galactosidase the changes are reversible and are shown to be due to lattice repacking. On cooling, the area of the protein surface involved in lattice contacts increases by 50 %. There are substantial alterations in intermolecular contacts, these changes being dominated by the long, polar side-chains. For entropic reasons such side-chains, as well as surface solvent molecules, tend to be somewhat disordered at room temperature but can form extensive hydrogen-bonded networks on cooling. Low-temperature density measurements suggest that, at least in some cases, the beneficial effect of cryosolvents may be due to a density increase on vitrification which reduces the volume of bulk solvent that needs to be expelled from the crystal. Analysis of beta-galactosidase and several other proteins suggests that both intramolecular and intermolecular contact interfaces can be perturbed by cryocooling but that the changes tend to be more dramatic in the latter case. The temperature-dependence of the intermolecular interactions suggests that caution may be necessary in interpreting protein-protein and protein-nucleic acid interactions based on low-temperature crystal structures.
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Affiliation(s)
- D H Juers
- Institute of Molecular Biology Howard Hughes Medical Institute and Department of Physics, 1229 University of Oregon, Eugene, OR 97403-1229, USA
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22
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de Bakker PI, Hünenberger PH, McCammon JA. Molecular dynamics simulations of the hyperthermophilic protein sac7d from Sulfolobus acidocaldarius: contribution of salt bridges to thermostability. J Mol Biol 1999; 285:1811-30. [PMID: 9917414 DOI: 10.1006/jmbi.1998.2397] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Hyperthermophilic proteins often possess an increased number of surface salt bridges compared with their mesophilic homologues. However, salt bridges are generally thought to be of minor importance in protein stability at room temperature. In an effort to understand why this may no longer be true at elevated temperatures, we performed molecular dynamics simulations of the hyperthermophilic protein Sac7d at 300 K, 360 K, and 550 K. The three trajectories are stable on the nanosecond timescale, as evidenced by the analysis of several time-resolved properties. The simulations at 300 K and (to a lesser extent) 360 K are also compatible with nuclear Overhauser effect-derived distances. Raising the temperature from 300 K to 360 K results in a less favourable protein-solvent interaction energy, and a more favourable intraprotein interaction energy. Both effects are almost exclusively electrostatic in nature and dominated by contributions due to charged side-chains. The reduced solvation is due to a loss of spatial and orientational structure of water around charged side-chains, which is a consequence of the increased thermal motion in the solvent. The favourable change in the intraprotein Coulombic interaction energy is essentially due to the tightening of salt bridges. Assuming that charged side-chains are on average more distant from one another in the unfolded state than in the folded state, it follows that salt bridges may contribute to protein stability at elevated temperatures because (i) the solvation free energy of charged side-chains is more adversely affected in the unfolded state than in the folded state by an increase in temperature, and (ii) due to the tightening of salt bridges, unfolding implies a larger unfavourable increase in the intraprotein Coulombic energy at higher temperature. Possible causes for the unexpected stability of the protein at 550 K are also discussed.
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Affiliation(s)
- P I de Bakker
- Department of Medicinal Chemistry, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, 3508 TB, The Netherlands.
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23
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Wang Z, Zhu G, Huang Q, Qian M, Shao M, Jia Y, Tang Y. X-ray studies on cross-linked lysozyme crystals in acetonitrile-water mixture. BIOCHIMICA ET BIOPHYSICA ACTA 1998; 1384:335-44. [PMID: 9659395 DOI: 10.1016/s0167-4838(98)00027-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Tetragonal crystals of hen egg white lysozyme were cross-linked and subjected to X-ray diffraction study in acetonitrile-water media with different acetonitrile concentrations. Crystals in neat acetonitrile did not scatter X-ray well. Structures of crystals in neat water, in 90% and 95% acetonitrile, and crystal back-soaked from acetonitrile to water, were determined to about 2 A resolution. For crystals in both 90% acetonitrile, and crystal back-soaked from acetonitrile to water, were determined to about 2 A resolution. For crystals in both 90% and 95% acetonitrile, only one protein-bond acetonitrile molecule is found in the active site cleft, and its location and binding-protein mode is similar to the C subunit of polysaccharide. The alteration in conformation and hydrogen-bond pattern involving water as solvent causes the reduction of the protein's flexibility in organic media. The back-soaked crystal regained its ordinary three-dimensional structure in water.
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Affiliation(s)
- Z Wang
- Department of Chemistry, Peking University, Beijing, China
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24
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Urabe H, Sugawara Y, Ataka M, Rupprecht A. Low-frequency Raman spectra of lysozyme crystals and oriented DNA films: dynamics of crystal water. Biophys J 1998; 74:1533-40. [PMID: 9512049 PMCID: PMC1299499 DOI: 10.1016/s0006-3495(98)77865-8] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We observed low-frequency Raman spectra of tetragonal lysozyme crystals and DNA films, with varying water content of the samples. The spectra are fitted well by sums of relaxation modes and damped harmonic oscillators in the region from approximately 1 cm(-1) to 250 cm(-1). The relaxation modes are due to crystal water, and the distribution of relaxation times is determined. In wet samples, the relaxation time of a small part of the water molecules is a little longer than that of bulk water. The relaxation time of a considerable part of the crystal water, which belongs mainly to the secondary hydration shell, is an order of magnitude longer than that of bulk water. Furthermore, the relaxation time of some water molecules in the primary hydration shell of semidry samples is shorter than we expected. Thus we have shown that low-frequency Raman measurements combined with properly oriented samples can give specific information on the dynamics of hydration water in the ps range. On the other hand, we concluded, based on polarized Raman spectra of lysozyme crystals, that the damped oscillators correspond to essentially intramolecular vibrational modes.
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Affiliation(s)
- H Urabe
- Tokyo Kasei Gakuin University, Aihara, Machida, Japan.
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25
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Aibara S, Shibata K, Morita Y. Protein crystallization in microgravity. UCHU SEIBUTSU KAGAKU 1997; 11:339-45. [PMID: 11541767 DOI: 10.2187/bss.11.339] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A space experiment involving protein crystallization was conducted in a microgravity environment using the space shuttle "Endeavour" of STS-47, on a 9-day mission from September 12th to 20th in 1992. The crystallization was carried out according to a batch method, and 5 proteins were selected as flight samples for crystallization. Two of these proteins: hen egg-white lysozyme and co-amino acid: pyruvate aminotransferase from Pseudomonas sp. F-126, were obtained as single crystals of good diffraction quality. Since 1992 we have carried out several space experiments for protein crystallization aboard space shuttles and the space station MIR. Our experimental results obtained mainly from hen egg-white lysozyme are described below, focusing on the effects of microgravity on protein crystal growth.
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Affiliation(s)
- S Aibara
- Research Institute for Food Science, Kyoto University.
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26
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Wallace AC, Borkakoti N, Thornton JM. TESS: a geometric hashing algorithm for deriving 3D coordinate templates for searching structural databases. Application to enzyme active sites. Protein Sci 1997; 6:2308-23. [PMID: 9385633 PMCID: PMC2143595 DOI: 10.1002/pro.5560061104] [Citation(s) in RCA: 257] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
It is well established that sequence templates such as those in the PROSITE and PRINTS databases are powerful tools for predicting the biological function and tertiary structure for newly derived protein sequences. The number of X-ray and NMR protein structures is increasing rapidly and it is apparent that a 3D equivalent of the sequence templates is needed. Here, we describe an algorithm called TESS that automatically derives 3D templates from structures deposited in the Brookhaven Protein Data Bank. While a new sequence can be searched for sequence patterns, a new structure can be scanned against these 3D templates to identify functional sites. As examples, 3D templates are derived for enzymes with an O-His-O "catalytic triad" and for the ribonucleases and lysozymes. When these 3D templates are applied to a large data set of nonidentical proteins, several interesting hits are located. This suggests that the development of a 3D template database may help to identify the function of new protein structures, if unknown, as well as to design proteins with specific functions.
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Affiliation(s)
- A C Wallace
- Department of Biochemistry and Molecular Biology, University College, London, England
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27
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Abstract
Advances in experimental and computational techniques have reaffirmed the role of protein X-ray crystallography as one of the primary providers of structural information both to enhance our fundamental understanding of biological systems and also to assist the design and optimization of important therapeutics. Today, the most important challenge facing macromolecular X-ray crystallography is the need to grow suitable crystals of a given protein. Once this has been accomplished, most often the question is not whether the structure will be solved but rather how fast this will be done. A dramatic example of this is the crystal structure of cytochrome c oxidase. The search for crystallization conditions took about 15 years and then the structure was solved in about one year.
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Affiliation(s)
- J P Wery
- Research Technologies & Proteins, Lilly Corporate Center, Indianapolis, Indiana, 46285, USA.
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28
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Otting G, Liepinsh E, Halle B, Frey U. NMR identification of hydrophobic cavities with low water occupancies in protein structures using small gas molecules. NATURE STRUCTURAL BIOLOGY 1997; 4:396-404. [PMID: 9145111 DOI: 10.1038/nsb0597-396] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Magnetization transfer through dipole-dipole interactions (nuclear Overhauser effects, NOEs) between water protons and the protons lining two small hydrophobic cavities in hen egg-white lysozyme demonstrates the presence of water molecules with occupancies of approximately 10-50%. Similarly, NOEs were observed between the cavity protons and the protons of hydrogen, methane, ethylene or cyclopropane applied at 1-200 bar pressure. These gases can thus be used as general NMR indicators of empty or partially hydrated hydrophobic cavities in proteins. All gases reside in the cavities for longer than 1 ns in marked contrast to common belief that gas diffusion in proteins is not much slower than in water. Binding to otherwise empty cavities may be a major aspect of the anesthetic effect of small organic gas molecules.
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Affiliation(s)
- G Otting
- Karolinska Institute, Department of Medical Biochemistry and Biophysics, Stockholm, Sweden. G.O. go@mfn ki se
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29
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Chayen NE, Boggon TJ, Cassetta A, Deacon A, Gleichmann T, Habash J, Harrop SJ, Helliwell JR, Nieh YP, Peterson MR, Raftery J, Snell EH, Hädener A, Niemann AC, Siddons DP, Stojanoff V, Thompson AW, Ursby T, Wulff M. Trends and challenges in experimental macromolecular crystallography. Q Rev Biophys 1996; 29:227-78. [PMID: 8968112 DOI: 10.1017/s0033583500005837] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Macromolecular X-ray crystallography underpins the vigorous field of structural molecular biology having yielded many protein, nucleic acid and virus structures in fine detail. The understanding of the recognition by these macromolecules, as receptors, of their cognate ligands involves the detailed study of the structural chemistry of their molecular interactions. Also these structural details underpin the rational design of novel inhibitors in modern drug discovery in the pharmaceutical industry. Moreover, from such structures the functional details can be inferred, such as the biological chemistry of enzyme reactivity. There is then a vast number and range of types of biological macromolecules that potentially could be studied. The completion of the protein primary sequencing of the yeast genome, and the human genome sequencing project comprising some 105proteins that is underway, raises expectations for equivalent three dimensional structural databases.
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Affiliation(s)
- N E Chayen
- Biophysics Section, Blackett Laboratory, Imperial College of Science, Technology and Medicine, London, UK.
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30
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Rejto PA, Freer ST. Protein conformational substates from X-ray crystallography. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 1996; 66:167-96. [PMID: 9175428 DOI: 10.1016/s0079-6107(97)85629-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- P A Rejto
- Agouron Pharmaceuticals Inc., San Diego, CA 92121-1121, USA
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31
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Young AC, Tilton RF, Dewan JC. Thermal expansion of hen egg-white lysozyme. Comparison of the 1.9 A resolution structures of the tetragonal form of the enzyme at 100 K and 298 K. J Mol Biol 1994; 235:302-17. [PMID: 8289250 DOI: 10.1016/s0022-2836(05)80034-8] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The average structural and dynamic properties of tetragonal hen egg-white lysozyme have been compared, in structures refined at 1.9 A resolution, using data collected at 100 K and 298 K. The molecule expands by 1.8% over this temperature range with the expansion occurring primarily in its small sub-atomic-sized spaces in an anisotropic manner. Hen egg-white lysozyme consists of two domains: domain 1 (residues 40 to 88) is composed primarily of beta-sheet and is observed to expand by only 0.3%; domain 2 (residues 1 to 39 and 89 to 129) is chiefly alpha-helix and is observed to expand by 2.2%. This is consistent with previous observations that proteins composed primarily of alpha-helix expand more with temperature than do those composed primarily of beta-sheet. The largest movement in the molecule is undergone by the two domains of the structure that move further apart as the temperature is raised. This motion is not a cleft opening but rather consists of a tilt by 2.3 degrees of domain 1 away from domain 2. Within the individual domains the largest movement is undergone by loop T1 of domain 2, consisting of residues 17 to 23. This loop moves in the opposite direction to the rest of the molecule as the temperature is raised. Average temperature factors for the room-temperature and low-temperature structures are 15.2 A2 and 8.1 A2, respectively, when all protein atoms are considered, while these values are 14.0 A2 and 7.8 A2, when only main-chain atoms (N, C alpha, C) are taken into account. An examination of the main-chain averaged B-factor per residue shows that residues involved in intermolecular protein-protein contacts, with symmetry-related molecules, have somewhat lower B-factors than the average and undergo smaller than average changes in B-factor as the temperature is lowered.
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Affiliation(s)
- A C Young
- Department of Chemistry, New York University, New York 10003
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