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Kashefolgheta S, Wang S, Acree WE, Hünenberger PH. Evaluation of nine condensed-phase force fields of the GROMOS, CHARMM, OPLS, AMBER, and OpenFF families against experimental cross-solvation free energies. Phys Chem Chem Phys 2021; 23:13055-13074. [PMID: 34105547 PMCID: PMC8207520 DOI: 10.1039/d1cp00215e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 04/28/2021] [Indexed: 12/02/2022]
Abstract
Experimental solvation free energies are nowadays commonly included as target properties in the validation of condensed-phase force fields, sometimes even in their calibration. In a previous article [Kashefolgheta et al., J. Chem. Theory. Comput., 2020, 16, 7556-7580], we showed how the involved comparison between experimental and simulation results could be made more systematic by considering a full matrix of cross-solvation free energies . For a set of N molecules that are all in the liquid state under ambient conditions, such a matrix encompasses N×N entries for considering each of the N molecules either as solute (A) or as solvent (B). In the quoted study, a cross-solvation matrix of 25 × 25 experimental value was introduced, considering 25 small molecules representative for alkanes, chloroalkanes, ethers, ketones, esters, alcohols, amines, and amides. This experimental data was used to compare the relative accuracies of four popular condensed-phase force fields, namely GROMOS-2016H66, OPLS-AA, AMBER-GAFF, and CHARMM-CGenFF. In the present work, the comparison is extended to five additional force fields, namely GROMOS-54A7, GROMOS-ATB, OPLS-LBCC, AMBER-GAFF2, and OpenFF. Considering these nine force fields, the correlation coefficients between experimental values and simulation results range from 0.76 to 0.88, the root-mean-square errors (RMSEs) from 2.9 to 4.8 kJ mol-1, and average errors (AVEEs) from -1.5 to +1.0 kJ mol-1. In terms of RMSEs, GROMOS-2016H66 and OPLS-AA present the best accuracy (2.9 kJ mol-1), followed by OPLS-LBCC, AMBER-GAFF2, AMBER-GAFF, and OpenFF (3.3 to 3.6 kJ mol-1), and then by GROMOS-54A7, CHARM-CGenFF, and GROMOS-ATB (4.0 to 4.8 kJ mol-1). These differences are statistically significant but not very pronounced, and are distributed rather heterogeneously over the set of compounds within the different force fields.
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Affiliation(s)
- Sadra Kashefolgheta
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCICH-8093 ZürichSwitzerland+41 44 632 55 03
| | - Shuzhe Wang
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCICH-8093 ZürichSwitzerland+41 44 632 55 03
| | - William E. Acree
- Department of Chemistry, University of North Texas1155 Union Circle Drive #305070DentonTexas 76203USA
| | - Philippe H. Hünenberger
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCICH-8093 ZürichSwitzerland+41 44 632 55 03
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2
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Kashefolgheta S, Oliveira MP, Rieder SR, Horta BAC, Acree WE, Hünenberger PH. Evaluating Classical Force Fields against Experimental Cross-Solvation Free Energies. J Chem Theory Comput 2020; 16:7556-7580. [DOI: 10.1021/acs.jctc.0c00688] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Sadra Kashefolgheta
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCI, CH-8093 Zürich, Switzerland
| | - Marina P. Oliveira
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCI, CH-8093 Zürich, Switzerland
| | - Salomé R. Rieder
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCI, CH-8093 Zürich, Switzerland
| | - Bruno A. C. Horta
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil
| | - William E. Acree
- Department of Chemistry, University of North Texas, 1155 Union Circle Drive #305070, Denton, Texas 76203, United States
| | - Philippe H. Hünenberger
- Laboratorium für Physikalische Chemie, ETH Zürich, ETH-Hönggerberg, HCI, CH-8093 Zürich, Switzerland
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Požar M, Jukić I, Lovrinčević B. Thermodynamic, structural and dynamic properties of selected non-associative neat liquids. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2020; 32:405101. [PMID: 32412441 DOI: 10.1088/1361-648x/ab935d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/14/2020] [Indexed: 06/11/2023]
Abstract
Non-associative neat liquids benzene, acetone and carbon tetrachloride have been examined via molecular dynamics simulations. Several models of each neat liquid have been simulated, and selected thermodynamic and structural results are presented. However, the models have been compared mainly in terms of their dynamic quantities. Since models are rarely parametrized with the dynamic properties in mind, the principal goal of this work is to present quantities such as the power spectra, rotational correlation functions and relaxation times, diffusion coefficients and self and distinct parts of the van Hove functions in relation to available experimental data. The general trends of the calculated data provide a benchmark for the behavior of neat simple liquids which will be built upon in the cases of mixtures with associative liquids.
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Affiliation(s)
- Martina Požar
- University of Split, Faculty of Science, Rud-era Boškovića 33, 21000 Split, Croatia
| | - Ivo Jukić
- University of Split, Faculty of Science, Rud-era Boškovića 33, 21000 Split, Croatia
| | - Bernarda Lovrinčević
- University of Split, Faculty of Science, Rud-era Boškovića 33, 21000 Split, Croatia
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4
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Kubincová A, Riniker S, Hünenberger PH. Reaction-field electrostatics in molecular dynamics simulations: development of a conservative scheme compatible with an atomic cutoff. Phys Chem Chem Phys 2020; 22:26419-26437. [DOI: 10.1039/d0cp03835k] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Shifting and switching schemes are developed to enable strict energy conservation in molecular dynamics simulations relying on reaction-field electrostatic (as well as Lennard-Jones) interactions with an atom-based cutoff truncation.
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Affiliation(s)
| | - Sereina Riniker
- Laboratory of Physical Chemistry
- ETH Zurich
- 8093 Zurich
- Switzerland
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5
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Lonardi A, Oborský P, Hünenberger PH. Solvent-Modulated Influence of Intramolecular Hydrogen-Bonding on the Conformational Properties of the Hydroxymethyl Group in Glucose and Galactose: A Molecular Dynamics Simulation Study. Helv Chim Acta 2016. [DOI: 10.1002/hlca.201600158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Alice Lonardi
- Laboratory of Physical Chemistry; ETH Hönggerberg; HCI; CH-8093 Zürich Switzerland
| | - Pavel Oborský
- Laboratory of Physical Chemistry; ETH Hönggerberg; HCI; CH-8093 Zürich Switzerland
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6
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Pechlaner M, Reif MM, Oostenbrink C. Reparametrisation of united-atom amine solvation in the GROMOS force field. Mol Phys 2016. [DOI: 10.1080/00268976.2016.1255797] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Maria Pechlaner
- Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Vienna, Austria
| | - Maria M. Reif
- Physics Department T38, Technische Universität München, Garching, Germany
| | - Chris Oostenbrink
- Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, Vienna, Austria
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7
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Horta BAC, Merz PT, Fuchs PFJ, Dolenc J, Riniker S, Hünenberger PH. A GROMOS-Compatible Force Field for Small Organic Molecules in the Condensed Phase: The 2016H66 Parameter Set. J Chem Theory Comput 2016; 12:3825-50. [DOI: 10.1021/acs.jctc.6b00187] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bruno A. C. Horta
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil
| | - Pascal T. Merz
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Patrick F. J. Fuchs
- Institut Jacques Monod, UMR 7592 CNRS, Université Paris-Diderot, Sorbonne Paris Cité, F-75205 Paris, France
| | - Jozica Dolenc
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Chemistry,
Biology and Pharmacy Information Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Sereina Riniker
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
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8
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Reif MM, Hünenberger PH. Origin of Asymmetric Solvation Effects for Ions in Water and Organic Solvents Investigated Using Molecular Dynamics Simulations: The Swain Acity-Basity Scale Revisited. J Phys Chem B 2016; 120:8485-517. [PMID: 27173101 DOI: 10.1021/acs.jpcb.6b02156] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The asymmetric solvation of ions can be defined as the tendency of a solvent to preferentially solvate anions over cations or cations over anions, at identical ionic charge magnitudes and effective sizes. Taking water as a reference, these effects are quantified experimentally for many solvents by the relative acity (A) and basity (B) parameters of the Swain scale. The goal of the present study is to investigate the asymmetric solvation of ions using molecular dynamics simulations, and to connect the results to this empirical scale. To this purpose, the charging free energies of alkali and halide ions, and of their hypothetical oppositely charged counterparts, are calculated in a variety of solvents. In a first set of calculations, artificial solvent models are considered that present either a charge or a shape asymmetry at the molecular level. The solvation asymmetry, probed by the difference in charging free energy between the two oppositely charged ions, is found to encompass a term quadratic in the ion charge, related to the different solvation structures around the anion and cation, and a term linear in the ion charge, related to the solvation structure around the uncharged ion-sized cavity. For these simple solvent models, the two terms are systematically counteracting each other, and it is argued that only the quadratic term should be retained when comparing the results of simulations involving physical solvents to experimental data. In a second set of calculations, 16 physical solvents are considered. The theoretical estimates for the acity A are found to correlate very well with the Swain parameters, whereas the correlation for B is very poor. Based on this observation, the Swain scale is reformulated into a new scale involving an asymmetry parameter Σ, positive for acitic solvents and negative for basitic ones, and a polarity parameter Π. This revised scale has the same predictive power as the original scale, but it characterizes asymmetry in an absolute sense, the atomistic simulations playing the role of an extra-thermodynamic assumption, and is optimally compatible with the simulation results. Considering the 55 solvents in the Swain set, it is observed that a moderate basity (Σ between -0.9 and -0.3, related to electronic polarization) represents the baseline for most solvents, while a highly variable acity (Σ between 0.0 and 3.0, related to hydrogen-bond donor capacity modulated by inductive effects) represents a landmark of protic solvents.
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Affiliation(s)
- Maria M Reif
- Physics Department (T38), Technische Universität München , D-85748 Garching, Germany
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9
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Pothoczki S, Temleitner L, Pusztai L. Structure of Neat Liquids Consisting of (Perfect and Nearly) Tetrahedral Molecules. Chem Rev 2015; 115:13308-61. [DOI: 10.1021/acs.chemrev.5b00308] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Szilvia Pothoczki
- Institute for Solid State
Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly Thege út 29-33, Budapest, H-1121 Hungary
| | - László Temleitner
- Institute for Solid State
Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly Thege út 29-33, Budapest, H-1121 Hungary
| | - László Pusztai
- Institute for Solid State
Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, Konkoly Thege út 29-33, Budapest, H-1121 Hungary
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10
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Lin Z, van Gunsteren WF. Effects of Polarizable Solvent Models upon the Relative Stability of an α-Helical and a β-Hairpin Structure of an Alanine Decapeptide. J Chem Theory Comput 2015; 11:1983-6. [DOI: 10.1021/acs.jctc.5b00210] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Zhixiong Lin
- Laboratory of Physical
Chemistry, Swiss Federal Institute of Technology, ETH, 8093 Zürich, Zürich, Switzerland
| | - Wilfred F. van Gunsteren
- Laboratory of Physical
Chemistry, Swiss Federal Institute of Technology, ETH, 8093 Zürich, Zürich, Switzerland
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11
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Szklarczyk OM, Bachmann SJ, van Gunsteren WF. A polarizable empirical force field for molecular dynamics simulation of liquid hydrocarbons. J Comput Chem 2014; 35:789-801. [PMID: 26248885 DOI: 10.1002/jcc.23551] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 12/22/2013] [Accepted: 01/13/2014] [Indexed: 12/17/2022]
Abstract
Electronic polarizability is usually treated implicitly in molecular simulations, which may lead to imprecise or even erroneous molecular behavior in spatially electronically inhomogeneous regions of systems such as proteins, membranes, interfaces between compounds, or mixtures of solvents. The majority of available molecular force fields and molecular dynamics simulation software packages does not account explicitly for electronic polarization. Even the simplest charge-on-spring (COS) models have only been developed for few types of molecules. In this work, we report a polarizable COS model for cyclohexane, as this molecule is a widely used solvent, and for linear alkanes, which are also used as solvents, and are the precursors of lipids, amino acid side chains, carbohydrates, or nucleic acid backbones. The model is an extension of a nonpolarizable united-atom model for alkanes that had been calibrated against experimental values of the density, the heat of vaporization and the Gibbs free energy of hydration for each alkane. The latter quantity was used to calibrate the parameters governing the interaction of the polarizable alkanes with water. Subsequently, the model was tested for other structural, thermodynamic, dielectric, and dynamic properties such as trans/gauche ratios, excess free energy, static dielectric permittivity, and self-diffusion. A good agreement with the experimental data for a large set of properties for each considered system was obtained, resulting in a transferable set of polarizable force-field parameters for CH2, CH3, and CH4 moieties.
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Affiliation(s)
- Oliwia M Szklarczyk
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology ETH, 8093, Zürich, Switzerland
| | - Stephan J Bachmann
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology ETH, 8093, Zürich, Switzerland
| | - Wilfred F van Gunsteren
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology ETH, 8093, Zürich, Switzerland
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12
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Caballero NB, Zuriaga M, Carignano MA, Serra P. Molecular kinetics of solid and liquid CHCl3. Chem Phys Lett 2013. [DOI: 10.1016/j.cplett.2013.08.105] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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13
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Caballero NB, Zuriaga M, Carignano M, Serra P. The plastic and liquid phases of CCl3Br studied by molecular dynamics simulations. J Chem Phys 2012; 136:094515. [DOI: 10.1063/1.3692605] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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14
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Zuriaga M, Carignano M, Serra P. Rotational relaxation characteristics of the monoclinic phase of CCl4. J Chem Phys 2011; 135:044504. [DOI: 10.1063/1.3614417] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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15
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Kunz APE, Eichenberger AP, van Gunsteren WF. A simple, efficient polarizable molecular model for liquid carbon tetrachloride. Mol Phys 2011. [DOI: 10.1080/00268976.2010.533208] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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16
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Hansen HS, Hünenberger PH. A reoptimized GROMOS force field for hexopyranose-based carbohydrates accounting for the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers. J Comput Chem 2010; 32:998-1032. [PMID: 21387332 DOI: 10.1002/jcc.21675] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 08/12/2010] [Accepted: 08/17/2010] [Indexed: 11/07/2022]
Abstract
This article presents a reoptimization of the GROMOS 53A6 force field for hexopyranose-based carbohydrates (nearly equivalent to 45A4 for pure carbohydrate systems) into a new version 56A(CARBO) (nearly equivalent to 53A6 for non-carbohydrate systems). This reoptimization was found necessary to repair a number of shortcomings of the 53A6 (45A4) parameter set and to extend the scope of the force field to properties that had not been included previously into the parameterization procedure. The new 56A(CARBO) force field is characterized by: (i) the formulation of systematic build-up rules for the automatic generation of force-field topologies over a large class of compounds including (but not restricted to) unfunctionalized polyhexopyranoses with arbritrary connectivities; (ii) the systematic use of enhanced sampling methods for inclusion of experimental thermodynamic data concerning slow or unphysical processes into the parameterization procedure; and (iii) an extensive validation against available experimental data in solution and, to a limited extent, theoretical (quantum-mechanical) data in the gas phase. At present, the 56A(CARBO) force field is restricted to compounds of the elements C, O, and H presenting single bonds only, no oxygen functions other than alcohol, ether, hemiacetal, or acetal, and no cyclic segments other than six-membered rings (separated by at least one intermediate atom). After calibration, this force field is shown to reproduce well the relative free energies of ring conformers, anomers, epimers, hydroxymethyl rotamers, and glycosidic linkage conformers. As a result, the 56A(CARBO) force field should be suitable for: (i) the characterization of the dynamics of pyranose ring conformational transitions (in simulations on the microsecond timescale); (ii) the investigation of systems where alternative ring conformations become significantly populated; (iii) the investigation of anomerization or epimerization in terms of free-energy differences; and (iv) the design of simulation approaches accelerating the anomerization process along an unphysical pathway.
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Affiliation(s)
- Halvor S Hansen
- Laboratorium für Physikalische Chemie, ETH Zürich, CH-8093 Zürich, Switzerland
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17
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Affiliation(s)
- Zhixiong Lin
- a Laboratory of Physical Chemistry , Swiss Federal Institute of Technology , ETH, 8093 Zürich, Switzerland
- b School of Life Sciences and Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China (USTC) , Hefei, Anhui 230027, People's Republic of China
| | - Anna-Pitschna Kunz
- a Laboratory of Physical Chemistry , Swiss Federal Institute of Technology , ETH, 8093 Zürich, Switzerland
| | - Wilfred F. van Gunsteren
- a Laboratory of Physical Chemistry , Swiss Federal Institute of Technology , ETH, 8093 Zürich, Switzerland
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18
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Park SM, Nguyen PH, Stock G. Molecular dynamics simulation of cooling: Heat transfer from a photoexcited peptide to the solvent. J Chem Phys 2009; 131:184503. [DOI: 10.1063/1.3259971] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
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19
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Rey R. Quantitative characterization of orientational order in liquid carbon tetrachloride. J Chem Phys 2007; 126:164506. [PMID: 17477613 DOI: 10.1063/1.2720840] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
A simple geometrical construct is proposed for a clear-cut classification of the relative orientation between two tetrahedral molecules in terms of six orientational classes. When applied to sort out configurations from condensed phase simulations, it leads to a quantitative characterization of orientational order: A definite percentage for each class is obtained as a function of the distance between molecular centers. The basic picture that emerges, for liquid carbon tetrachloride, is that the dominant configuration for each distance is such that the number of chlorines in between both carbons diminishes with increasing separation, with a configuration here termed edge-to-face being the dominant one at contact. Regarding the range of orientational order, remnants are still noticeable at approximately 20 A, i.e., up to the fourth solvation shell. Beyond this distance the distributions are hardly distinguishable from the analytical predictions for random orientation. The analysis of the small fluctuations at such long distances shows that there are no significant differences between the ranges of positional and orientational order.
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Affiliation(s)
- Rossend Rey
- Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Campus Nord B4-B5, Barcelona 08034, Spain
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20
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Rothschild WG. Enhanced near-neighbour aggregation of dichloro- and trichloromethane in liquid methane solution from molecular dynamics simulation of radial site–site distribution functions: a simple predictor of solute–solvent compatibility. Mol Phys 2006. [DOI: 10.1080/00268970601014336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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21
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Oostenbrink C, Villa A, Mark AE, van Gunsteren WF. A biomolecular force field based on the free enthalpy of hydration and solvation: the GROMOS force-field parameter sets 53A5 and 53A6. J Comput Chem 2004; 25:1656-76. [PMID: 15264259 DOI: 10.1002/jcc.20090] [Citation(s) in RCA: 2796] [Impact Index Per Article: 139.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Successive parameterizations of the GROMOS force field have been used successfully to simulate biomolecular systems over a long period of time. The continuing expansion of computational power with time makes it possible to compute ever more properties for an increasing variety of molecular systems with greater precision. This has led to recurrent parameterizations of the GROMOS force field all aimed at achieving better agreement with experimental data. Here we report the results of the latest, extensive reparameterization of the GROMOS force field. In contrast to the parameterization of other biomolecular force fields, this parameterization of the GROMOS force field is based primarily on reproducing the free enthalpies of hydration and apolar solvation for a range of compounds. This approach was chosen because the relative free enthalpy of solvation between polar and apolar environments is a key property in many biomolecular processes of interest, such as protein folding, biomolecular association, membrane formation, and transport over membranes. The newest parameter sets, 53A5 and 53A6, were optimized by first fitting to reproduce the thermodynamic properties of pure liquids of a range of small polar molecules and the solvation free enthalpies of amino acid analogs in cyclohexane (53A5). The partial charges were then adjusted to reproduce the hydration free enthalpies in water (53A6). Both parameter sets are fully documented, and the differences between these and previous parameter sets are discussed.
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Affiliation(s)
- Chris Oostenbrink
- Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH-Hönggerberg, 8093 Zürich, Switzerland
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23
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Rey R, Pardo LC, Llanta E, Ando K, López DO, Tamarit JL, Barrio M. X-ray and molecular dynamics study of liquid structure in pure methylchloromethane compounds ((CH3)4−nCCln). J Chem Phys 2000. [DOI: 10.1063/1.481348] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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24
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Abstract
Two neuropeptides, substance P (SP) and SP-tyrosine-8 (SP-Y8), have been studied by molecular dynamics (MD) simulation in a TIP3P water/CCl4 biphasic solvent system as a mimic for the water-membrane system. Initially, distance restraints derived from NMR nuclear Overhauser enhancements (NOE) were incorporated in the restrained MD (RMD) in the equilibration stage of the simulation. The starting orientation/position of the peptides for the MD simulation was either parallel to the water/CCl4 interface or in a perpendicular/insertion mode. In both cases the peptides equilibrated and adopted a near-parallel orientation within approximately 250 ps. After equilibration, the conformation and orientation of the peptides, the solvation of both the backbone and the side chain of the residues, hydrogen bonding, and the dynamics of the peptides were analyzed from trajectories obtained in the RMD or the subsequent free MD (where the NOE restraints were removed). These analyses showed that the peptide backbone of nearly all residues are either solvated by water or are hydrogen-bonded. This is seen to be an important factor against the insertion mode of interaction. Most of the interactions with the hydrophobic phase come from the hydrophobic interactions of the side chains of Pro-4, Phe-7, Phe-8, Leu-10, and Met-11 for SP, and Phe-7, Leu-10, Met-11 and, to a lesser extent, Tyr-8 in SP-Y8. Concerted conformational transitions took place in the time frame of hundreds of picoseconds. The concertedness of the transition was due to the tendency of the peptide to maintain the necessary secondary structure to position the peptide properly with respect to the water/CCl4 interface.
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Affiliation(s)
- T Wymore
- Department of Chemistry, University of Missouri, Columbia, Missouri 65211 USA
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