1
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Clark JA, Prabhu VM, Douglas JF. Molecular Dynamics Simulation of the Influence of Temperature and Salt on the Dynamic Hydration Layer in a Model Polyzwitterionic Polymer PAEDAPS. J Phys Chem B 2023; 127:8185-8198. [PMID: 37668318 PMCID: PMC10578162 DOI: 10.1021/acs.jpcb.3c03654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/06/2023]
Abstract
We investigate the hydration of poly(3-[2-(acrylamido) ethyldimethylammonio] propanesulfonate) over a range of temperatures in pure water and with the inclusion of 0.1 mol/L NaCl using atomistic molecular dynamics simulation. Drawing on concepts drawn from the field of glass-forming liquids, we use the Debye-Waller parameter () for describing the water mobility gradient around the polybetaine backbone extending to an overall distance ≈18 Å. The water mobility in this layer is defined through the mean-square water molecule displacement at a time on the order of water's β-relaxation time. The brushlike topology of polybetaines leads to two regions in the dynamic hydration layer. The inner region of ≈10.5 Å is explored by pendant group conformational motions, and the outer region of ≈7.5 Å represents an extended layer of reduced water mobility relative to bulk water. The dynamic hydration layer extends far beyond the static hydration layer, adjacent to the polymer.
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Affiliation(s)
- Jennifer A. Clark
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Vivek M. Prabhu
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Jack F. Douglas
- Materials Science and Engineering Division, Material Measurement Laboratory, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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2
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Sauer MA, Heyden M. Frequency-Selective Anharmonic Mode Analysis of Thermally Excited Vibrations in Proteins. J Chem Theory Comput 2023; 19:5481-5490. [PMID: 37515568 PMCID: PMC10624555 DOI: 10.1021/acs.jctc.2c01309] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/31/2023]
Abstract
Low-frequency molecular vibrations at far-infrared frequencies are thermally excited at room temperature. As a consequence, thermal fluctuations are not limited to the immediate vicinity of local minima on the potential energy surface, and anharmonic properties cannot be ignored. The latter is particularly relevant in molecules with multiple conformations, such as proteins and other biomolecules. However, existing theoretical and computational frameworks for the analysis of molecular vibrations have so far been limited by harmonic or quasi-harmonic approximations, which are ill-suited to describe anharmonic low-frequency vibrations. Here, we introduce a fully anharmonic analysis of molecular vibrations based on a time correlation formalism that eliminates the need for harmonic or quasi-harmonic approximations. We use molecular dynamics simulations of a small protein to demonstrate that this new approach, in contrast to harmonic and quasi-harmonic normal modes, correctly identifies the collective degrees of freedom associated with molecular vibrations at any given frequency. This allows us to unambiguously characterize the anharmonic character of low-frequency vibrations in the far-infrared spectrum.
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Affiliation(s)
- Michael A Sauer
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
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3
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Bubon T, Zdorevskyi O, Perepelytsya S. Molecular dynamics study of collective water vibrations in a DNA hydration shell. EUROPEAN BIOPHYSICS JOURNAL : EBJ 2023; 52:69-79. [PMID: 36920489 DOI: 10.1007/s00249-023-01638-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/16/2023] [Accepted: 02/18/2023] [Indexed: 03/16/2023]
Abstract
The structure of DNA double helix is stabilized by water molecules and metal counterions that form the ion-hydration shell around the macromolecule. Understanding the role of the ion-hydration shell in the physical mechanisms of the biological functioning of DNA requires detailed studies of its structure and dynamics at the atomistic level. In the present work, the study of collective vibrations of water molecules around the DNA double helix was performed within the framework of classical all-atom molecular dynamics methods. Calculating the vibrational density of states, the vibrations of water molecules in the low-frequency spectra ranged from [Formula: see text]30 to [Formula: see text]300 [Formula: see text] were analyzed for the case of different regions of the DNA double helix (minor groove, major groove, and phosphate groups). The analysis revealed significant differences in the collective vibrations behavior of water molecules in the DNA hydration shell, compared to the vibrations of bulk water. All low-frequency modes of the DNA ion-hydration shell are shifted by about 15-20 [Formula: see text] towards higher frequencies, which is more significant for water molecules in the minor groove region of the double helix. The interactions of water molecules with the atoms of the macromolecule induce intensity decrease of the mode of hydrogen-bond symmetrical stretching near 150 [Formula: see text], leading to the disappearance of this mode in the DNA spectra. The obtained results can provide an interpretation of the experimental data for DNA low-frequency spectra and may be important for the understanding of the processes of indirect protein-nucleic recognition.
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Affiliation(s)
- Tetiana Bubon
- Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 14b, Metrolohichna Str., Kyiv, 03143, Ukraine.
- Condensed Matter and Statistical Physics, Abdus Salam International Centre for Theoretical Physics, Strada Costiera, 11, Trieste, 34151, Italy.
| | - Oleksii Zdorevskyi
- Department of Physics, University of Helsinki, Gustaf Hällströmin katu 2, Helsinki, 00014, Finland
| | - Sergiy Perepelytsya
- Bogolyubov Institute for Theoretical Physics of the National Academy of Sciences of Ukraine, 14b, Metrolohichna Str., Kyiv, 03143, Ukraine
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4
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Biedermannová L, Černý J, Malý M, Nekardová M, Schneider B. Knowledge-based prediction of DNA hydration using hydrated dinucleotides as building blocks. Acta Crystallogr D Struct Biol 2022; 78:1032-1045. [PMID: 35916227 PMCID: PMC9344474 DOI: 10.1107/s2059798322006234] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 06/14/2022] [Indexed: 11/19/2022] Open
Abstract
Water plays an important role in stabilizing the structure of DNA and mediating its interactions. Here, the hydration of DNA was analyzed in terms of dinucleotide fragments from an ensemble of 2727 nonredundant DNA chains containing 41 853 dinucleotides and 316 265 associated first-shell water molecules. The dinucleotides were classified into categories based on their 16 sequences and the previously determined structural classes known as nucleotide conformers (NtCs). The construction of hydrated dinucleotide building blocks allowed dinucleotide hydration to be calculated as the probability of water density distributions. Peaks in the water densities, known as hydration sites (HSs), uncovered the interplay between base and sugar-phosphate hydration in the context of sequence and structure. To demonstrate the predictive power of hydrated DNA building blocks, they were then used to predict hydration in an independent set of crystal and NMR structures. In ten tested crystal structures, the positions of predicted HSs and experimental waters were in good agreement (more than 40% were within 0.5 Å) and correctly reproduced the known features of DNA hydration, for example the `spine of hydration' in B-DNA. Therefore, it is proposed that hydrated building blocks can be used to predict DNA hydration in structures solved by NMR and cryo-EM, thus providing a guide to the interpretation of experimental data and computer models. The data for the hydrated building blocks and the predictions are available for browsing and visualization at the website https://watlas.datmos.org/watna/.
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Affiliation(s)
- Lada Biedermannová
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Jiří Černý
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Michal Malý
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Michaela Nekardová
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
| | - Bohdan Schneider
- Institute of Biotechnology of the Czech Academy of Sciences, BIOCEV, Průmyslová 595, 252 50 Vestec, Czech Republic
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5
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Päslack C, Schäfer LV, Heyden M. Protein flexibility reduces solvent-mediated friction barriers of ligand binding to a hydrophobic surface patch. Phys Chem Chem Phys 2021; 23:5665-5672. [PMID: 33656505 DOI: 10.1039/d1cp00181g] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Solvent fluctuations have been explored in detail for idealized and rigid hydrophobic model systems, but so far it has remained unclear how internal protein motions and their coupling to the surrounding solvent affect the dynamics of ligand binding to biomolecular surfaces. Here, molecular dynamics simulations were used to elucidate the solvent-mediated binding of a model ligand to the hydrophobic surface patch of ubiquitin. The ligand's friction profiles reveal pronounced long-time correlations and enhanced friction in the vicinity of the protein, similar to idealized hydrophobic surfaces. Interestingly, these effects are shaped by internal protein motions. Protein flexibility modulates water density fluctuations near the hydrophobic surface patch and smooths out the friction profile of ligand binding.
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Affiliation(s)
- Christopher Päslack
- Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780 Bochum, Germany.
| | - Lars V Schäfer
- Theoretical Chemistry, Faculty of Chemistry and Biochemistry, Ruhr University Bochum, D-44780 Bochum, Germany.
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, AZ 85287-1604, USA.
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6
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Kripotou S, Zafeiris K, Culebras-Martínez M, Gallego Ferrer G, Kyritsis A. Dynamics of hydration water in gelatin and hyaluronic acid hydrogels. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2019; 42:109. [PMID: 31444585 DOI: 10.1140/epje/i2019-11871-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Accepted: 07/18/2019] [Indexed: 06/10/2023]
Abstract
We employed broadband dielectric spectroscopy (BDS), for the investigation of the water dynamics in partially hydrated hyaluronic acid (HA), and gelatin (Gel), enzymatically crosslinked hydrogels, in the water fraction ranges [Formula: see text]. Our results indicate that at low hydrations ([Formula: see text]), where the dielectric response of the hydrogels is identical during cooling and heating, water plasticizes strongly the polymeric matrix and is organized in clusters giving rise to [Formula: see text]-process, secondary water relaxation and to an additional slower relaxation process. This later process has been found to be related with the dc charge conductivity and can be described in terms of the conduction current relaxation mechanism. At slightly higher hydrations, however, always below the hydration level where ice is formed during cooling, we have recorded in HA hydrogel a strong water dielectric relaxation process, [Formula: see text], which has Arrhenius-like temperature dependence and large time scale resembling relaxation processes recorded in bulk low density amorphous solid water structures. This relaxation process shows a strong-to-fragile transition at [Formula: see text]C and our data suggest that the VTF-like process recorded at [Formula: see text]C is controlled by the same molecular process like long range charge transport. In addition, our data imply that the crossover temperature is related with the onset of structural rearrangements (increase in configurational entropy) of the macromolecules. In partially crystallized hydrogels ([Formula: see text]) HA exhibits at low temperatures the ice dielectric process consistent with the bulk hexagonal ice, whereas Gel hydrogel exhibits as main low temperature process a slow relaxation process that refers to open tetrahedral structures of water similar to low density amorphous ice structures and to bulk cubic ice. Regarding the water secondary relaxation processes, we have shown that the [Formula: see text]-process and the [Formula: see text] process are activated in water hydrogen bond networks with different structures.
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Affiliation(s)
- Sotiria Kripotou
- National Technical University of Athens, Physics Department, Iroon Polytechneiou 9, Zografou Campus, 15780, Athens, Greece
| | - Konstantinos Zafeiris
- National Technical University of Athens, Physics Department, Iroon Polytechneiou 9, Zografou Campus, 15780, Athens, Greece
| | - Maria Culebras-Martínez
- Centre for Biomaterials and Tissue Engineering (CBIT), Universitat Politècnica de València, Camino de vera s/n, 46022, Valencia, Spain
| | - Gloria Gallego Ferrer
- Centre for Biomaterials and Tissue Engineering (CBIT), Universitat Politècnica de València, Camino de vera s/n, 46022, Valencia, Spain
- Biomedical Research Networking Centre in Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Valencia, Spain
| | - Apostolos Kyritsis
- National Technical University of Athens, Physics Department, Iroon Polytechneiou 9, Zografou Campus, 15780, Athens, Greece.
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7
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Päslack C, Schäfer LV, Heyden M. Atomistic characterization of collective protein–water–membrane dynamics. Phys Chem Chem Phys 2019; 21:15958-15965. [DOI: 10.1039/c9cp00725c] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Water mediates correlated vibrations of atoms of protein and membrane bilayer surfaces.
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Affiliation(s)
- Christopher Päslack
- Center for Theoretical Chemistry
- Faculty of Chemistry and Biochemistry
- Ruhr-University Bochum
- D-44780 Bochum
- Germany
| | - Lars V. Schäfer
- Center for Theoretical Chemistry
- Faculty of Chemistry and Biochemistry
- Ruhr-University Bochum
- D-44780 Bochum
- Germany
| | - Matthias Heyden
- School of Molecular Sciences
- Arizona State University
- Tempe
- USA
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8
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Päslack C, Smith JC, Heyden M, Schäfer LV. Hydration-mediated stiffening of collective membrane dynamics by cholesterol. Phys Chem Chem Phys 2019; 21:10370-10376. [DOI: 10.1039/c9cp01431d] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydration water governs the cholesterol-induced changes in collective headgroup dynamics in lipid bilayers.
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Affiliation(s)
- Christopher Päslack
- Theoretical Chemistry
- Faculty of Chemistry and Biochemistry
- Ruhr University Bochum
- D-44780 Bochum
- Germany
| | - Jeremy C. Smith
- Center for Molecular Biophysics
- Oak Ridge National Laboratory
- Oak Ridge
- USA
- Department of Biochemistry and Cellular and Molecular Biology
| | - Matthias Heyden
- School of Molecular Sciences
- Arizona State University
- Tempe
- USA
| | - Lars V. Schäfer
- Theoretical Chemistry
- Faculty of Chemistry and Biochemistry
- Ruhr University Bochum
- D-44780 Bochum
- Germany
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9
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Ahmed S, Pasti A, Fernández-Terán RJ, Ciardi G, Shalit A, Hamm P. Aqueous solvation from the water perspective. J Chem Phys 2018; 148:234505. [PMID: 29935500 DOI: 10.1063/1.5034225] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The response of water re-solvating a charge-transfer dye (deprotonated Coumarin 343) after photoexcitation has been measured by means of transient THz spectroscopy. Two steps of increasing THz absorption are observed, a first ∼10 ps step on the time scale of Debye relaxation of bulk water and a much slower step on a 3.9 ns time scale, the latter of which reflecting heating of the bulk solution upon electronic relaxation of the dye molecules from the S1 back into the S0 state. As an additional reference experiment, the hydroxyl vibration of water has been excited directly by a short IR pulse, establishing that the THz signal measures an elevated temperature within ∼1 ps. This result shows that the first step upon dye excitation (10 ps) is not limited by the response time of the THz signal; it rather reflects the reorientation of water molecules in the solvation layer. The apparent discrepancy between the relatively slow reorientation time and the general notion that water is among the fastest solvents with a solvation time in the sub-picosecond regime is discussed. Furthermore, non-equilibrium molecular dynamics simulations have been performed, revealing a close-to-quantitative agreement with experiment, which allows one to disentangle the contribution of heating to the overall THz response from that of water orientation.
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Affiliation(s)
- Saima Ahmed
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Andrea Pasti
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | | | - Gustavo Ciardi
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Andrey Shalit
- Department of Chemistry, University of Zurich, Zurich, Switzerland
| | - Peter Hamm
- Department of Chemistry, University of Zurich, Zurich, Switzerland
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10
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Pressure effects on collective density fluctuations in water and protein solutions. Proc Natl Acad Sci U S A 2017; 114:11410-11415. [PMID: 29073065 DOI: 10.1073/pnas.1705279114] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Neutron Brillouin scattering and molecular dynamics simulations have been used to investigate protein hydration water density fluctuations as a function of pressure. Our results show significant differences between the pressure and density dependence of collective dynamics in bulk water and in concentrated protein solutions. Pressure-induced changes in the tetrahedral order of the water HB network have direct consequences for the high-frequency sound velocity and damping coefficients, which we find to be a sensitive probe for changes in the HB network structure as well as the wetting of biomolecular surfaces.
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11
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Pathak AK, Bandyopadhyay T. Water isotope effect on the thermostability of a polio viral RNA hairpin: A metadynamics study. J Chem Phys 2017; 146:165104. [DOI: 10.1063/1.4982049] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Affiliation(s)
- Arup K. Pathak
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai 400 085, India
| | - Tusar Bandyopadhyay
- Theoretical Chemistry Section, Bhabha Atomic Research Centre, Mumbai 400 085, India
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12
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On the ability of molecular dynamics simulation and continuum electrostatics to treat interfacial water molecules in protein-protein complexes. Sci Rep 2016; 6:38259. [PMID: 27905545 PMCID: PMC5131287 DOI: 10.1038/srep38259] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Accepted: 10/28/2016] [Indexed: 01/23/2023] Open
Abstract
Interfacial waters are increasingly appreciated as playing a key role in protein-protein interactions. We report on a study of the prediction of interfacial water positions by both Molecular Dynamics and explicit solvent-continuum electrostatics based on the Dipolar Poisson-Boltzmann Langevin (DPBL) model, for three test cases: (i) the barnase/barstar complex (ii) the complex between the DNase domain of colicin E2 and its cognate Im2 immunity protein and (iii) the highly unusual anti-freeze protein Maxi which contains a large number of waters in its interior. We characterize the waters at the interface and in the core of the Maxi protein by the statistics of correctly predicted positions with respect to crystallographic water positions in the PDB files as well as the dynamic measures of diffusion constants and position lifetimes. Our approach provides a methodology for the evaluation of predicted interfacial water positions through an investigation of water-mediated inter-chain contacts. While our results show satisfactory behaviour for molecular dynamics simulation, they also highlight the need for improvement of continuum methods.
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13
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Wei G, Xi W, Nussinov R, Ma B. Protein Ensembles: How Does Nature Harness Thermodynamic Fluctuations for Life? The Diverse Functional Roles of Conformational Ensembles in the Cell. Chem Rev 2016; 116:6516-51. [PMID: 26807783 PMCID: PMC6407618 DOI: 10.1021/acs.chemrev.5b00562] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
All soluble proteins populate conformational ensembles that together constitute the native state. Their fluctuations in water are intrinsic thermodynamic phenomena, and the distributions of the states on the energy landscape are determined by statistical thermodynamics; however, they are optimized to perform their biological functions. In this review we briefly describe advances in free energy landscape studies of protein conformational ensembles. Experimental (nuclear magnetic resonance, small-angle X-ray scattering, single-molecule spectroscopy, and cryo-electron microscopy) and computational (replica-exchange molecular dynamics, metadynamics, and Markov state models) approaches have made great progress in recent years. These address the challenging characterization of the highly flexible and heterogeneous protein ensembles. We focus on structural aspects of protein conformational distributions, from collective motions of single- and multi-domain proteins, intrinsically disordered proteins, to multiprotein complexes. Importantly, we highlight recent studies that illustrate functional adjustment of protein conformational ensembles in the crowded cellular environment. We center on the role of the ensemble in recognition of small- and macro-molecules (protein and RNA/DNA) and emphasize emerging concepts of protein dynamics in enzyme catalysis. Overall, protein ensembles link fundamental physicochemical principles and protein behavior and the cellular network and its regulation.
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Affiliation(s)
- Guanghong Wei
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Wenhui Xi
- State Key Laboratory of Surface Physics, Key Laboratory for Computational Physical Sciences (MOE), and Department of Physics, Fudan University, Shanghai, P. R. China
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, USA
- Sackler Inst. of Molecular Medicine Department of Human Genetics and Molecular Medicine Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc. Cancer and Inflammation Program, National Cancer Institute, Frederick, Maryland 21702, USA
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14
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Xu M, Caflisch A, Hamm P. Protein Structural Memory Influences Ligand Binding Mode(s) and Unbinding Rates. J Chem Theory Comput 2016; 12:1393-9. [PMID: 26799675 DOI: 10.1021/acs.jctc.5b01052] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The binding of small molecules (e.g., natural ligands, metabolites, and drugs) to proteins governs most biochemical pathways and physiological processes. Here, we use molecular dynamics to investigate the unbinding of dimethyl sulfoxide (DMSO) from two distinct states of a small rotamase enzyme, the FK506-binding protein (FKBP). These states correspond to the FKBP protein relaxed with and without DMSO in the active site. Since the time scale of ligand unbinding (2-20 ns) is faster than protein relaxation (100 ns), a novel methodology is introduced to relax the protein without having to introduce an artificial constraint. The simulation results show that the unbinding time is an order of magnitude longer for dissociation from the DMSO-bound state (holo-relaxed). That is, the actual rate of unbinding depends on the state of the protein, with the protein having a long-lived memory. The rate thus depends on the concentration of the ligand as the apo and holo states reflect low and high concentrations of DMSO, respectively. Moreover, there are multiple binding modes in the apo-relaxed state, while a single binding mode dominates the holo-relaxed state in which DMSO acts as hydrogen bond acceptor from the backbone NH of Ile56, as in the crystal structure of the DMSO/FKBP complex. The solvent relaxes very fast (∼1 ns) close to the NH of Ile56 and with the same time scale of the protein far away from the active site. These results have implications for high-throughput docking, which makes use of a rigid structure of the protein target.
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Affiliation(s)
- Min Xu
- Department of Biochemistry and ‡Department of Chemistry, University of Zürich , Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - Amedeo Caflisch
- Department of Biochemistry and ‡Department of Chemistry, University of Zürich , Winterthurerstrasse 190, Zürich CH-8057, Switzerland
| | - Peter Hamm
- Department of Biochemistry and ‡Department of Chemistry, University of Zürich , Winterthurerstrasse 190, Zürich CH-8057, Switzerland
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15
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Fogarty AC, Potestio R, Kremer K. Adaptive resolution simulation of a biomolecule and its hydration shell: Structural and dynamical properties. J Chem Phys 2015; 142:195101. [DOI: 10.1063/1.4921347] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Aoife C. Fogarty
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Raffaello Potestio
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Kurt Kremer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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