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Hatch HW, Bergonzo C, Blanco MA, Yuan G, Grudinin S, Lund M, Curtis JE, Grishaev AV, Liu Y, Shen VK. Anisotropic coarse-grain Monte Carlo simulations of lysozyme, lactoferrin, and NISTmAb by precomputing atomistic models. J Chem Phys 2024; 161:094113. [PMID: 39234967 DOI: 10.1063/5.0224809] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2024] [Accepted: 08/16/2024] [Indexed: 09/06/2024] Open
Abstract
We develop a multiscale coarse-grain model of the NIST Monoclonal Antibody Reference Material 8671 (NISTmAb) to enable systematic computational investigations of high-concentration physical instabilities such as phase separation, clustering, and aggregation. Our multiscale coarse-graining strategy captures atomic-resolution interactions with a computational approach that is orders of magnitude more efficient than atomistic models, assuming the biomolecule can be decomposed into one or more rigid bodies with known, fixed structures. This method reduces interactions between tens of thousands of atoms to a single anisotropic interaction site. The anisotropic interaction between unique pairs of rigid bodies is precomputed over a discrete set of relative orientations and stored, allowing interactions between arbitrarily oriented rigid bodies to be interpolated from the precomputed table during coarse-grained Monte Carlo simulations. We present this approach for lysozyme and lactoferrin as a single rigid body and for the NISTmAb as three rigid bodies bound by a flexible hinge with an implicit solvent model. This coarse-graining strategy predicts experimentally measured radius of gyration and second osmotic virial coefficient data, enabling routine Monte Carlo simulation of medically relevant concentrations of interacting proteins while retaining atomistic detail. All methodologies used in this work are available in the open-source software Free Energy and Advanced Sampling Simulation Toolkit.
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Affiliation(s)
- Harold W Hatch
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Christina Bergonzo
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Biomolecular Structure and Function Group, Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Marco A Blanco
- Discovery Pharmaceutical Sciences, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania 19486, USA
| | - Guangcui Yuan
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Sergei Grudinin
- CNRS, Grenoble INP, LJK, Université Grenoble Alpes, 38000 Grenoble, France
| | - Mikael Lund
- Division of Computational Chemistry, Lund University, Lund, Sweden
| | - Joseph E Curtis
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
| | - Alexander V Grishaev
- Institute for Bioscience and Biotechnology Research, Rockville, Maryland 20850, USA
- Biomolecular Structure and Function Group, Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
| | - Yun Liu
- Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, College of Engineering, University of Delaware, Newark, Delaware 19711, USA
| | - Vincent K Shen
- Chemical Informatics Research Group, Chemical Sciences Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-8380, USA
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2
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Dandekar BR, Majumdar BB, Mondal J. Nonmonotonic Modulation of the Protein-Ligand Recognition Event by Inert Crowders. J Phys Chem B 2023; 127:7449-7461. [PMID: 37590118 DOI: 10.1021/acs.jpcb.3c03946] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
The ubiquitous event of a protein recognizing small molecules or ligands at its native binding site is crucial for initiating major biological processes. However, how a crowded environment, as is typically represented by a cellular interior, would modulate the protein-ligand search process is largely debated. Excluded volume-based theory suggests that the presence of an inert crowder would reinforce a steady stabilization and enhancement of the protein-ligand recognition process. Here, we counter this long-held perspective via the molecular dynamics simulation and Markov state model of the protein-ligand recognition event in the presence of inert crowders. Specifically, we demonstrate that, depending on concentration, even purely inert crowders can exert a nonmonotonic effect via either stabilizing or destabilizing the protein-ligand binding event. Analysis of the kinetic network of binding pathways reveals that the crowders would either modulate precedent non-native on-pathway intermediates or would devise additional ones in a multistate recognition event across a wide range of concentrations. As an important insight, crowders gradually shift the relative transitional preference of these intermediates toward a native-bound state, with ligand residence time at the binding pocket dictating the trend of nonmonotonic concentration dependence by simple inert crowders.
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3
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Freites JA, Louis MN, Tobias DJ. Insights into the solubility of γ $$ \gamma $$ D-crystallin from multiscale atomistic simulations. J Comput Chem 2023. [PMID: 37093714 DOI: 10.1002/jcc.27116] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 03/31/2023] [Accepted: 04/12/2023] [Indexed: 04/25/2023]
Abstract
The molecular basis underlying the rich phase behavior of globular proteins remains poorly understood. We use atomistic multiscale molecular simulations to model the solution-state conformational dynamics and interprotein interactions of γ $$ \gamma $$ D-crystallin and its P23T-R36S mutant, which drastically limits the protein solubility, at both infinite dilution and at a concentration where the mutant fluid phase and crystalline phase coexist. We find that while the mutant conserves the protein fold, changes to the surface exposure of residues in the neighborhood of residue-36 enhance protein-protein interactions and develop specific protein-protein contacts found in the protein crystal lattice.
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Affiliation(s)
- J Alfredo Freites
- Department of Chemistry, University of California, Irvine, California, USA
| | - Mohab N Louis
- Department of Chemistry, University of California, Irvine, California, USA
| | - Douglas J Tobias
- Department of Chemistry, University of California, Irvine, California, USA
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4
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Diessner EM, Freites JA, Tobias DJ, Butts CT. Network Hamiltonian Models for Unstructured Protein Aggregates, with Application to γD-Crystallin. J Phys Chem B 2023; 127:685-697. [PMID: 36637342 PMCID: PMC10437096 DOI: 10.1021/acs.jpcb.2c07672] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Network Hamiltonian models (NHMs) are a framework for topological coarse-graining of protein-protein interactions, in which each node corresponds to a protein, and edges are drawn between nodes representing proteins that are noncovalently bound. Here, this framework is applied to aggregates of γD-crystallin, a structural protein of the eye lens implicated in cataract disease. The NHMs in this study are generated from atomistic simulations of equilibrium distributions of wild-type and the cataract-causing variant W42R in solution, performed by Wong, E. K.; Prytkova, V.; Freites, J. A.; Butts, C. T.; Tobias, D. J. Molecular Mechanism of Aggregation of the Cataract-Related γD-Crystallin W42R Variant from Multiscale Atomistic Simulations. Biochemistry2019, 58 (35), 3691-3699. Network models are shown to successfully reproduce the aggregate size and structure observed in the atomistic simulation, and provide information about the transient protein-protein interactions therein. The system size is scaled from the original 375 monomers to a system of 10000 monomers, revealing a lowering of the upper tail of the aggregate size distribution of the W42R variant. Extrapolation to higher and lower concentrations is also performed. These results provide an example of the utility of NHMs for coarse-grained simulation of protein systems, as well as their ability to scale to large system sizes and high concentrations, reducing computational costs while retaining topological information about the system.
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Affiliation(s)
- Elizabeth M Diessner
- Department of Chemistry, University of California, Irvine, California92697, United States
| | - J Alfredo Freites
- Department of Chemistry, University of California, Irvine, California92697, United States
| | - Douglas J Tobias
- Department of Chemistry, University of California, Irvine, California92697, United States
| | - Carter T Butts
- Departments of Sociology, Statistics, Computer Science, and EECS, University of California, Irvine, California92697, United States
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5
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Anisotropic Protein-Protein Interactions in Dilute and Concentrated Solutions. J Colloid Interface Sci 2022; 629:794-804. [DOI: 10.1016/j.jcis.2022.08.054] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2022] [Revised: 08/08/2022] [Accepted: 08/09/2022] [Indexed: 11/21/2022]
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6
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Yin F, Khago D, Martin RW, Butts CT. Bayesian analysis of static light scattering data for globular proteins. PLoS One 2021; 16:e0258429. [PMID: 34648536 PMCID: PMC8516215 DOI: 10.1371/journal.pone.0258429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Accepted: 09/28/2021] [Indexed: 11/18/2022] Open
Abstract
Static light scattering is a popular physical chemistry technique that enables calculation of physical attributes such as the radius of gyration and the second virial coefficient for a macromolecule (e.g., a polymer or a protein) in solution. The second virial coefficient is a physical quantity that characterizes the magnitude and sign of pairwise interactions between particles, and hence is related to aggregation propensity, a property of considerable scientific and practical interest. Estimating the second virial coefficient from experimental data is challenging due both to the degree of precision required and the complexity of the error structure involved. In contrast to conventional approaches based on heuristic ordinary least squares estimates, Bayesian inference for the second virial coefficient allows explicit modeling of error processes, incorporation of prior information, and the ability to directly test competing physical models. Here, we introduce a fully Bayesian model for static light scattering experiments on small-particle systems, with joint inference for concentration, index of refraction, oligomer size, and the second virial coefficient. We apply our proposed model to study the aggregation behavior of hen egg-white lysozyme and human γS-crystallin using in-house experimental data. Based on these observations, we also perform a simulation study on the primary drivers of uncertainty in this family of experiments, showing in particular the potential for improved monitoring and control of concentration to aid inference.
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Affiliation(s)
- Fan Yin
- Department of Statistics, University of California at Irvine, Irvine, CA, United States of America
| | - Domarin Khago
- Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, Maryland, United States of America
| | - Rachel W. Martin
- Departments of Chemistry and Molecular Biology and Biochemistry, University of California at Irvine, Irvine, CA, United States of America
| | - Carter T. Butts
- Departments of Sociology, Statistics, Computer Science and EECS and Institute for Mathematical Behavioral Sciences, University of California at Irvine, Irvine, CA, United States of America
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7
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Sprague-Piercy MA, Rocha MA, Kwok AO, Martin RW. α-Crystallins in the Vertebrate Eye Lens: Complex Oligomers and Molecular Chaperones. Annu Rev Phys Chem 2021; 72:143-163. [PMID: 33321054 PMCID: PMC8062273 DOI: 10.1146/annurev-physchem-090419-121428] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
α-Crystallins are small heat-shock proteins that act as holdase chaperones. In humans, αA-crystallin is expressed only in the eye lens, while αB-crystallin is found in many tissues. α-Crystallins have a central domain flanked by flexible extensions and form dynamic, heterogeneous oligomers. Structural models show that both the C- and N-terminal extensions are important for controlling oligomerization through domain swapping. α-Crystallin prevents aggregation of damaged β- and γ-crystallins by binding to the client protein using a variety of binding modes. α-Crystallin chaperone activity can be compromised by mutation or posttranslational modifications, leading to protein aggregation and cataract. Because of their high solubility and their ability to form large, functional oligomers, α-crystallins are particularly amenable to structure determination by solid-state nuclear magnetic resonance (NMR) and solution NMR, as well as cryo-electron microscopy.
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Affiliation(s)
- Marc A Sprague-Piercy
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697, USA;
| | - Megan A Rocha
- Department of Chemistry, University of California, Irvine, California 92697, USA
| | - Ashley O Kwok
- Department of Chemistry, University of California, Irvine, California 92697, USA
| | - Rachel W Martin
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California 92697, USA;
- Department of Chemistry, University of California, Irvine, California 92697, USA
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8
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Hyltegren K, Polimeni M, Skepö M, Lund M. Integrating All-Atom and Coarse-Grained Simulations-Toward Understanding of IDPs at Surfaces. J Chem Theory Comput 2020; 16:1843-1853. [PMID: 32036660 DOI: 10.1021/acs.jctc.9b01041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We present a scheme for transferring conformational degrees of freedom from all-atom (AA) simulations of an intrinsically disordered protein (IDP) to coarse-grained (CG) Monte Carlo (MC) simulations using conformational swap moves. AA simulations of a single histatin 5 peptide in water were used to obtain a structural ensemble, which is reweighted in a CGMC simulation in the presence of a negatively charged surface. For efficient sampling, the AA trajectory was condensed using two approaches: RMSD clustering (based on the root-mean-square difference in atom positions) and a "naı̈ve" truncation, where only every 100th frame of the trajectory was included in the library. The results show that even libraries with few structures well reproduce the radius of gyration and interaction free energy as functions of the distance from the surface. We further observe that the surface slightly promotes the secondary structure of histatin 5 and more so if using explicit surface charges rather than smeared charges.
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Affiliation(s)
- Kristin Hyltegren
- Division of Theoretical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Marco Polimeni
- Division of Theoretical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden
| | - Marie Skepö
- Division of Theoretical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.,LINXS-Lund Institute of Advanced Neutron and X-ray Science, Scheelevägen 19, SE-223 70 Lund, Sweden
| | - Mikael Lund
- Division of Theoretical Chemistry, Lund University, P.O. Box 124, SE-221 00 Lund, Sweden.,LINXS-Lund Institute of Advanced Neutron and X-ray Science, Scheelevägen 19, SE-223 70 Lund, Sweden
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9
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Abstract
Comprehensive data about the composition and structure of cellular components have enabled the construction of quantitative whole-cell models. While kinetic network-type models have been established, it is also becoming possible to build physical, molecular-level models of cellular environments. This review outlines challenges in constructing and simulating such models and discusses near- and long-term opportunities for developing physical whole-cell models that can connect molecular structure with biological function.
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Affiliation(s)
- Michael Feig
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan 48824, USA;
- Laboratory for Biomolecular Function Simulation, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
| | - Yuji Sugita
- Laboratory for Biomolecular Function Simulation, RIKEN Center for Biosystems Dynamics Research, Kobe, Hyogo 650-0047, Japan
- Theoretical Molecular Science Laboratory, RIKEN Cluster for Pioneering Research, Wako, Saitama 351-0198, Japan
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10
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Qin S, Zhou HX. Calculation of Second Virial Coefficients of Atomistic Proteins Using Fast Fourier Transform. J Phys Chem B 2019; 123:8203-8215. [PMID: 31490691 DOI: 10.1021/acs.jpcb.9b06808] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The second virial coefficient, B2, measures a protein solution's deviation from ideal behavior. It is widely used to predict or explain solubility, crystallization condition, aggregation propensity, and critical temperature for liquid-liquid phase separation. B2 is determined by the interaction energy between two protein molecules and, specifically, by the integration of the Mayer f-function in the relative configurational space (translation and rotation) of the two molecules. Simple theoretical models, such as one attributed to Derjaguin, Landau, Verwey, and Overbeek (DLVO), can fit the dependence of B2 on salt concentrations. However, model parameters derived often are physically unrealistic and hardly transferable from protein to protein. Previous B2 calculations incorporating atomistic details were done with limited sampling in the configurational space, due to enormous computational cost. Our FMAP method, based on fast Fourier transform, can considerably accelerate such calculations, and here we adapt it to calculate B2 values for proteins represented at the atomic level in implicit solvent. After tuning of a single parameter in the energy function, FMAPB2 predicts well the B2 values for lysozyme and other proteins over wide ranges of solvent conditions (salt concentration, pH, and temperature). The method is available as a web server at http://pipe.rcc.fsu.edu/fmapb2 .
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Affiliation(s)
- Sanbo Qin
- Department of Chemistry and Department of Physics , University of Illinois at Chicago , Chicago , Illinois 60607 , United States.,Institute of Molecular Biophysics , Florida State University , Tallahassee , Florida 32306 , United States
| | - Huan-Xiang Zhou
- Department of Chemistry and Department of Physics , University of Illinois at Chicago , Chicago , Illinois 60607 , United States
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11
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Wong EK, Prytkova V, Freites JA, Butts CT, Tobias DJ. Molecular Mechanism of Aggregation of the Cataract-Related γD-Crystallin W42R Variant from Multiscale Atomistic Simulations. Biochemistry 2019; 58:3691-3699. [PMID: 31393108 DOI: 10.1021/acs.biochem.9b00208] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The mechanisms leading to aggregation of the crystallin proteins of the eye lens remain largely unknown. We use atomistic multiscale molecular simulations to model the solution-state conformational dynamics of γD-crystallin and its cataract-related W42R variant at both infinite dilution and physiologically relevant concentrations. We find that the W42R variant assumes a distinct conformation in solution that leaves the Greek key domains of the native fold largely unaltered but lacks the hydrophobic interdomain interface that is key to the stability of wild-type γD-crystallin. At physiologically relevant concentrations, exposed hydrophobic regions in this alternative conformation become primary sites for enhanced interprotein interactions leading to large-scale aggregation.
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Affiliation(s)
- Eric K Wong
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Vera Prytkova
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - J Alfredo Freites
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Carter T Butts
- Departments of Sociology, Electrical Engineering and Computer Science, and Statistics , University of California , Irvine , California 92697 , United States
| | - Douglas J Tobias
- Department of Chemistry , University of California , Irvine , California 92697 , United States
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12
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Majumdar BB, Prytkova V, Wong EK, Freites JA, Tobias DJ, Heyden M. Role of Conformational Flexibility in Monte Carlo Simulations of Many-Protein Systems. J Chem Theory Comput 2019; 15:1399-1408. [DOI: 10.1021/acs.jctc.8b00894] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Bibhab Bandhu Majumdar
- Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Vera Prytkova
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Eric K. Wong
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - J. Alfredo Freites
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Douglas J. Tobias
- Department of Chemistry, University of California, Irvine, Irvine, California 92697, United States
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, Tempe, Arizona 85287, United States
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13
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Majumdar BB, Ebbinghaus S, Heyden M. Macromolecular crowding effects in flexible polymer solutions. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2018. [DOI: 10.1142/s0219633618400060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Biological environments are often “crowded” due to high concentrations (300–400[Formula: see text]g/L) of macromolecules. Computational modeling approaches like Molecular Dynamics (MD), rigid-body Brownian Dynamics and Monte Carlo simulations have recently emerged, which allow to study the effects macromolecular crowding at a microscopic level and to provide complementary information to experiments. Here, we use a recently introduced multiple-conformation Monte Carlo (mcMC) approach in order to study the influence of intermolecular interactions on the structural equilibrium of flexible polyethylene glycol (PEG) polymers under self-crowding conditions. The large conformational space accessible to PEG polymers allows us to evaluate the general applicability of the mcMC approach, which describes the intramolecular degrees of freedom by a finite-size ensemble of discrete conformations. Despite the simplicity of the approach, we show that influences of intermolecular interactions on the intramolecular free energy surface can be described qualitatively using mcMC. By varying the magnitude of distinct terms in the intermolecular potential, we can further study the compensating effects of repulsive and nonspecific attractive intermolecular interactions, which favor compact and extended polymer states, respectively. We use our simulation results to derive an analytical model that describes the effects of intermolecular interactions on the stability of PEG polymer conformations as a function of the radius of gyration and the corresponding solvent accessible surface. We use this model to confirm the role of molecular surfaces for attractive interactions that can counteract excluded volume effects. Extrapolation of the model further allows for the analysis of scenarios that are not easily accessible to direct simulations as described here.
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Affiliation(s)
- Bibhab Bandhu Majumdar
- Theoretische Chemie, Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Simon Ebbinghaus
- Institute of Physical and Theoretical Chemistry, Technical University, Braunschweig, Rebenring 56, 38106 Braunschweig, Germany
| | - Matthias Heyden
- School of Molecular Sciences, Arizona State University, 551 E. University Dr., Tempe, AZ 85281, USA
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