1
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Tonti L, Floris FM. Hydrophilic Versus Hydrophobic Coupling in the Pressure Dependence of the Chemical Potential of Alkali Metal and Halide Ions in Water. J Phys Chem B 2022; 126:9325-9338. [PMID: 36326490 PMCID: PMC9677433 DOI: 10.1021/acs.jpcb.2c02373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We computed the chemical potential for some alkali metal ions (K+, Rb+, and Cs+) and two halide ions (Br- and I-) in aqueous solution at ambient T and various pressures in the range 1-8000 atm. Results were obtained from classic Monte Carlo simulations in the NPT ensemble by means of the free energy perturbation method. Here, the chemical potential is computed as the sum of a term relative to a Lennard-Jones solute and a term relative to the process in which this solute is transformed into the ion. Hydrophobic and hydrophilic features of these two components of the chemical potential show opposite behaviors under isothermal compression. The increase in pressure determines an increase in the hydrophobic component, which becomes more positive with a stronger effect for larger ions. Correspondingly, the values of the hydrophilic component become more negative for alkali ions, whereas they are only slightly affected by compression for halide ions. Hydrophobic-hydrophilic quasi-compensation in the slopes is observed for Rb+. For a smaller ion, such as K+, the dependence on pressure of the hydrophilic component is slightly dominant. For a larger ion, as observed in the cases of Cs+, Br-, and I-, the hydrophobic component assumes the determinant role. Pressure dependence of the chemical potential is little affected by corrections introduced for molecular potential truncation. This view can change for possible boundary artifacts that could have affected the static electrostatic potential. Some inference is obtained from comparison with experimental data at 1 atm on the free energy of hydration. Discrepancies show the characteristic asymmetry between cations and anions. The further addition of a correction based on the static potential significantly reduces these discrepancies with important error cancellation on the sum of chemical potentials of ions of opposite charge. The correction is applied also at higher pressures, and results are compared with those obtained by adding an alternative correction that is based on the water number density. Regardless of the ion, changes of the chemical potential induced by an increase in pressure appear to be dominated by the hydrophobic component, in particular when using the alternative correction. For bromide and iodide electrolytes, the two corrections give chemical potentials in good agreement.
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Affiliation(s)
- Luca Tonti
- Department
of Chemical Engineering, The University
of Manchester, M13 9PLManchester, U.K.,
| | - Franca Maria Floris
- Dipartimento
di Chimica e Chimica Industriale, Università
di Pisa, Via Giuseppe
Moruzzi 13, 56124Pisa, Italy,
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2
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Yadav A, Bandyopadhyay P, Coutsias EA, Dill KA. Crustwater: Modeling Hydrophobic Solvation. J Phys Chem B 2022; 126:6052-6062. [PMID: 35926838 PMCID: PMC9393863 DOI: 10.1021/acs.jpcb.2c02695] [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: 04/19/2022] [Revised: 07/13/2022] [Indexed: 11/29/2022]
Abstract
We describe Crustwater, a statistical mechanical model of nonpolar solvation in water. It treats bulk water using the Cage Water model and introduces a crust, i.e., a solvation shell of coordinated partially structured waters. Crustwater is analytical and fast to compute. We compute here solvation vs temperature over the liquid range, and vs pressure and solute size. Its thermal predictions are as accurate as much more costly explicit models such as TIP4P/2005. This modeling gives new insights into the hydrophobic effect: (1) that oil-water insolubility in cold water is due to solute-water (SW) translational entropy and not water-water (WW) orientations, even while hot water is dominated by WW cage breaking, and (2) that a size transition at the Angstrom scale, not the nanometer scale, takes place as previously predicted.
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Affiliation(s)
- Ajeet
Kumar Yadav
- School
of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Pradipta Bandyopadhyay
- School
of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Evangelos A. Coutsias
- Department
of Applied Mathematics and Statistics ; Laufer Center for Physical
and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794, United States
| | - Ken A. Dill
- Laufer
Center for Physical and Quantitative Biology; Department of Physics
and Astronomy ; Department of Chemistry, Stony Brook University, Stony
Brook, New York 11794, United States
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3
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Warmińska D, Śmiechowski M. Understanding ion–ion and ion–solvent interactions in aqueous solutions of morpholinium ionic liquids with N-acetyl-L-alaninate anion through partial molar properties and molecular dynamics simulations. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.118876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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4
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Sentell Z, Spooner J, Weinberg N. Molecular Dynamics Calculations of Partial Molar Volumes of Amino Acids in Aqueous Solutions. CAN J CHEM 2022. [DOI: 10.1139/cjc-2021-0217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Partial molar volumes of amino acids in their zwitterionic and molecular forms have been calculated using molecular dynamics simulations of these systems in aqueous solutions. Calculations performed with the TIP4P, SPC (rigid and flexible), SPC/E, and polarizable water models show that the choice of water model can have a significant impact on the calculated volumes. The effect of treatment of long-range electrostatic interactions on the calculated results was also investigated. Volumes obtained in simulations with a properly chosen water model fit well the experimental data for both molecular and zwitterionic forms of amino acids.
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Affiliation(s)
- Zachary Sentell
- University of the Fraser Valley, 1011, Department of Chemistry, Abbotsford, Canada
| | - Jacob Spooner
- University of the Fraser Valley, 1011, Department of Chemistry, Abbotsford, Canada, V2S 7M8
| | - Noham Weinberg
- University of the Fraser Valley, 1011, Department of Chemistry, Abbotsford, Canada, V2S 7M8
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5
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Yadav AK, Bandyopadhyay P, Urbic T, Dill KA. Analytical 2-Dimensional Model of Nonpolar and Ionic Solvation in Water. J Phys Chem B 2021; 125:1861-1873. [PMID: 33539097 PMCID: PMC7958497 DOI: 10.1021/acs.jpcb.0c10329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A goal in computational chemistry is computing hydration free energies of nonpolar and charged solutes accurately, but with much greater computational speeds than in today's explicit-water simulations. Here, we take one step in that direction: a simple model of solvating waters that is analytical and thus essentially instantaneous to compute. Each water molecule is a 2-dimensional dipolar hydrogen-bonding disk that interacts around small circular solutes with different nonpolar and charge interactions. The model gives good qualitative agreement with experiments. As a function of the solute radius, it gives the solvation free energy, enthalpy and entropy as a function of temperature for the inert gas series Ne, Ar, Kr, and Xe. For anions and cations, it captures relatively well the trends versus ion radius. This approach should be readily generalizable to three dimensions.
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Affiliation(s)
- Ajeet Kumar Yadav
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Pradipta Bandyopadhyay
- School of Computational and Integrative Sciences, Jawaharlal Nehru University, New Delhi 110067, India
| | - Tomaz Urbic
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000, Ljubljana, Slovenia
| | - Ken A Dill
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, New York, New York 11794, United States
- Department of Physics and Astronomy, Stony Brook University, New York, New York 11794, United States
- Department of Chemistry, Stony Brook University, New York, New York 11794, United States
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6
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Gasic AG, Cheung MS. A Tale of Two Desolvation Potentials: An Investigation of Protein Behavior under High Hydrostatic Pressure. J Phys Chem B 2020; 124:1619-1627. [DOI: 10.1021/acs.jpcb.9b10734] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Andrei G. Gasic
- Department of Physics, University of Houston, Houston, Texas 77204, United States
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
| | - Margaret S. Cheung
- Department of Physics, University of Houston, Houston, Texas 77204, United States
- Center for Theoretical Biological Physics, Rice University, Houston, Texas 77005, United States
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7
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Bianco V, Franzese G, Coluzza I. In Silico Evidence That Protein Unfolding is a Precursor of Protein Aggregation. Chemphyschem 2020; 21:377-384. [DOI: 10.1002/cphc.201900904] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/01/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Valentino Bianco
- Faculty of Chemistry, Chemical Physics Department, Universidad Complutense de Madrid, Plaza de las Ciencias Ciudad Universitaria Madrid 28040 Spain
| | - Giancarlo Franzese
- Secció de Física Estadística i Interdisciplinària-Departament de Física de la Matèria Condensada, Facultat de Física & Institute of Nanoscience and Nanotechnology (IN2UB) Universitat de Barcelona Martí i Franquès 1 08028 Barcelona Spain
| | - Ivan Coluzza
- CIC biomaGUNE Paseo Miramon 182 20014 San Sebastian Spain
- IKERBASQUE, Basque Foundation for Science 48013 Bilbao Spain
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8
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Cinar H, Fetahaj Z, Cinar S, Vernon RM, Chan HS, Winter RHA. Temperature, Hydrostatic Pressure, and Osmolyte Effects on Liquid-Liquid Phase Separation in Protein Condensates: Physical Chemistry and Biological Implications. Chemistry 2019; 25:13049-13069. [PMID: 31237369 DOI: 10.1002/chem.201902210] [Citation(s) in RCA: 79] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/23/2019] [Indexed: 01/04/2023]
Abstract
Liquid-liquid phase separation (LLPS) of proteins and other biomolecules play a critical role in the organization of extracellular materials and membrane-less compartmentalization of intra-organismal spaces through the formation of condensates. Structural properties of such mesoscopic droplet-like states were studied by spectroscopy, microscopy, and other biophysical techniques. The temperature dependence of biomolecular LLPS has been studied extensively, indicating that phase-separated condensed states of proteins can be stabilized or destabilized by increasing temperature. In contrast, the physical and biological significance of hydrostatic pressure on LLPS is less appreciated. Summarized here are recent investigations of protein LLPS under pressures up to the kbar-regime. Strikingly, for the cases studied thus far, LLPSs of both globular proteins and intrinsically disordered proteins/regions are typically more sensitive to pressure than the folding of proteins, suggesting that organisms inhabiting the deep sea and sub-seafloor sediments, under pressures up to 1 kbar and beyond, have to mitigate this pressure-sensitivity to avoid unwanted destabilization of their functional biomolecular condensates. Interestingly, we found that trimethylamine-N-oxide (TMAO), an osmolyte upregulated in deep-sea fish, can significantly stabilize protein droplets under pressure, pointing to another adaptive advantage for increased TMAO concentrations in deep-sea organisms besides the osmolyte's stabilizing effect against protein unfolding. As life on Earth might have originated in the deep sea, pressure-dependent LLPS is pertinent to questions regarding prebiotic proto-cells. Herein, we offer a conceptual framework for rationalizing the recent experimental findings and present an outline of the basic thermodynamics of temperature-, pressure-, and osmolyte-dependent LLPS as well as a molecular-level statistical mechanics picture in terms of solvent-mediated interactions and void volumes.
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Affiliation(s)
- Hasan Cinar
- Physical Chemistry I-Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Strasse 4a, 44227, Dortmund, Germany
| | - Zamira Fetahaj
- Physical Chemistry I-Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Strasse 4a, 44227, Dortmund, Germany
| | - Süleyman Cinar
- Physical Chemistry I-Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Strasse 4a, 44227, Dortmund, Germany
| | - Robert M Vernon
- Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Hue Sun Chan
- Department of Biochemistry, Faculty of Medicine, University of Toronto, Ontario, M5S 1A8, Canada.,Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Ontario, M5S 1A8, Canada
| | - Roland H A Winter
- Physical Chemistry I-Biophysical Chemistry, Faculty of Chemistry and Chemical Biology, TU Dortmund University, Otto-Hahn Strasse 4a, 44227, Dortmund, Germany
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9
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Pica A, Graziano G. On the ability of classic scaled particle theory to reproduce the cavity contact correlation function of water over a large hydrostatic pressure range. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.04.140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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10
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Urbic T, Dill KA. Analytical theory of the hydrophobic effect of solutes in water. Phys Rev E 2018; 96:032101. [PMID: 29347026 DOI: 10.1103/physreve.96.032101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2017] [Indexed: 11/07/2022]
Abstract
We develop an analytical statistical-mechanical model for hydrophobic solvation in water. In this three-dimensional Mercedes-Benz-like model, two neighboring waters have three possible interaction states: a radial van der Waals interaction, a tetrahedral orientation-dependent hydrogen-bonding interaction, or no interaction. Nonpolar solutes are modeled as van der Waals particles of different radii. The model is sufficiently simple that we can calculate the partition function and thermal and volumetric properties of solvation versus temperature, pressure, and solute radius. Predictions are in good agreement with results of Monte Carlo simulations. And their trends agree with experiments on hydrophobic solute insertion. The theory shows that first-shell waters are more highly structured than bulk waters, because of hydrogen bonding, and that that structure melts out faster with temperature than it does in bulk waters. Because the theory is analytical, it can explore a broad range of solvation properties and anomalies of water, at minimal computational expense.
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Affiliation(s)
- Tomaz Urbic
- University of Ljubljana, Faculty of Chemistry and Chemical Technology, Večna pot 113, SI-1000 Ljubljana, Slovenia
| | - Ken A Dill
- Laufer Center for Physical and Quantitative Biology, Stony Brook University, Stony Brook, New York 11794-5252, USA
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11
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Sumi T, Maruyama Y, Mitsutake A, Mochizuki K, Koga K. Application of reference‐modified density functional theory: Temperature and pressure dependences of solvation free energy. J Comput Chem 2017; 39:202-217. [DOI: 10.1002/jcc.25101] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Revised: 10/18/2017] [Accepted: 10/19/2017] [Indexed: 01/04/2023]
Affiliation(s)
- Tomonari Sumi
- Division of Superconducting and Functional MaterialsResearch Institute for Interdisciplinary Science, Okayama University, 3‐1‐1 Tsushima‐Naka, Kita‐kuOkayama700‐8530 Japan
- Department of Chemistry, Faculty of ScienceOkayama University, 3‐1‐1 Tsushima‐Naka, Kita‐kuOkayama700‐8530 Japan
| | - Yutaka Maruyama
- Co‐Design Team, FLAGSHIP 2020 Project, RIKEN Advanced Institute for Computational Science, 7‐1‐26, Minatojima‐minami‐machiKobe650‐0047 Japan
| | - Ayori Mitsutake
- Department of PhysicsKeio University, 3‐14‐1 Hiyoshi, Kohoku‐kuYokohama Kanagawa223–8522 Japan
| | - Kenji Mochizuki
- Division of Superconducting and Functional MaterialsResearch Institute for Interdisciplinary Science, Okayama University, 3‐1‐1 Tsushima‐Naka, Kita‐kuOkayama700‐8530 Japan
| | - Kenichiro Koga
- Division of Superconducting and Functional MaterialsResearch Institute for Interdisciplinary Science, Okayama University, 3‐1‐1 Tsushima‐Naka, Kita‐kuOkayama700‐8530 Japan
- Department of Chemistry, Faculty of ScienceOkayama University, 3‐1‐1 Tsushima‐Naka, Kita‐kuOkayama700‐8530 Japan
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12
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Floris FM. Excess Volumes from the Pressure Derivative of the Excess Chemical Potential: Testing Simple Models for Cavity Formation in Water. ACS OMEGA 2017; 2:6424-6436. [PMID: 31457245 PMCID: PMC6644935 DOI: 10.1021/acsomega.7b01157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2017] [Accepted: 09/22/2017] [Indexed: 06/10/2023]
Abstract
Excess volumes and excess compressibilities for hard spheres in water were computed by pressure derivatives of the excess chemical potential, which is equivalent to the work of cavity formation. This is relevant to the application of continuum solvation methods at various pressures. The excess chemical potential was modeled within phenomenological expressions for curved surfaces plus a pressure-volume term, for which two approaches were adopted, differing for the radius of the spherical volume. This implies a different dependence on pressure of parameters. In all cases, in the surface term, for the pressure derivative of parameters of the curvature function, use was made of the previously proposed expressions for the first two moments obtained from the density and radial distribution of oxygens in liquid water. Only for the parameter which has the dimension of surface tension (γ̃) was explicit dependence on pressure considered and results are affected by the specific polynomial used. In agreement with what inferred from simulation results obtained for cavities in TIP4P water, negative and positive adsorptions at the contact radius were extrapolated for a very large cavity at 1 and 8000 atm, respectively. The expressions here employed for the excess chemical potential predict the zero value of asymptotic adsorption to be at a pressure between 500 and 800 atm, which can be compared to results from the revised scaled particle theory. In the same range, for a nanometer-sized cavity, a change of behavior occurs regarding the ratio between the excess Helmholtz free energy and the product between pressure and excess volume.
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13
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Waage MH, Vlugt TJH, Kjelstrup S. Phase Diagram of Methane and Carbon Dioxide Hydrates Computed by Monte Carlo Simulations. J Phys Chem B 2017; 121:7336-7350. [DOI: 10.1021/acs.jpcb.7b03071] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Thijs J. H. Vlugt
- Engineering Thermodynamics, Process & Energy Department, Faculty of Mechanical, Maritime and Materials Engineering, Delft University of Technology, Leeghwaterstraat 39, 2628 CB Delft, The Netherlands
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14
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Krobath H, Chen T, Chan HS. Volumetric Physics of Polypeptide Coil–Helix Transitions. Biochemistry 2016; 55:6269-6281. [DOI: 10.1021/acs.biochem.6b00802] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Heinrich Krobath
- Departments of Biochemistry
and Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Tao Chen
- Departments of Biochemistry
and Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Hue Sun Chan
- Departments of Biochemistry
and Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada
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15
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16
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The formation of a cavity in water: Changes of water distribution and prediction of the excess chemical potential of a hard-sphere solute under increasing pressure. J Mol Liq 2016. [DOI: 10.1016/j.molliq.2016.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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17
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Vilseck JZ, Tirado-Rives J, Jorgensen WL. Determination of partial molar volumes from free energy perturbation theory. Phys Chem Chem Phys 2015; 17:8407-15. [PMID: 25589343 PMCID: PMC4872387 DOI: 10.1039/c4cp05304d] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Partial molar volume is an important thermodynamic property that gives insights into molecular size and intermolecular interactions in solution. Theoretical frameworks for determining the partial molar volume (V°) of a solvated molecule generally apply Scaled Particle Theory or Kirkwood-Buff theory. With the current abilities to perform long molecular dynamics and Monte Carlo simulations, more direct methods are gaining popularity, such as computing V° directly as the difference in computed volume from two simulations, one with a solute present and another without. Thermodynamically, V° can also be determined as the pressure derivative of the free energy of solvation in the limit of infinite dilution. Both approaches are considered herein with the use of free energy perturbation (FEP) calculations to compute the necessary free energies of solvation at elevated pressures. Absolute and relative partial molar volumes are computed for benzene and benzene derivatives using the OPLS-AA force field. The mean unsigned error for all molecules is 2.8 cm(3) mol(-1). The present methodology should find use in many contexts such as the development and testing of force fields for use in computer simulations of organic and biomolecular systems, as a complement to related experimental studies, and to develop a deeper understanding of solute-solvent interactions.
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Affiliation(s)
- Jonah Z Vilseck
- Department of Chemistry, Yale University, New Haven, Connecticut 06520-8107, USA.
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18
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Meng B, Ashbaugh HS. Effect of hydrostatic pressure on gas solubilization in micelles. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2015; 31:3318-3325. [PMID: 25730396 DOI: 10.1021/la503646z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Molecular dynamics simulations of anionic sodium decylsulfate and nonionic pentaethylene glycol monodecyl ether micelles in water have been performed to examine the impact of hydrostatic pressure on argon solubilization as a function of pressure. The potential-of-mean force between the micelles and argon demonstrates that nonpolar gases are attracted to the interiors of both micelles. The affinity of argon for micelle interiors, however, decreases with increasing pressure as a result of the comparatively higher molar volume of argon inside assemblies. We evaluate solubility enhancement coefficients, which describe the drop in the solute chemical potential as a function of the micellized surfactant concentration, to quantify the impact of micellization on gas solubilization. While argon is similarly attracted to the hydrophobic cores of both micelles, the gas is more effectively sequestered within nonionic micelles compared with anionic micelles as a result of salting out by charged head groups and accompanying counterions. The solubility enhancement coefficients of both micelles decrease with increasing pressure, reflecting the changing forces observed in the potentials-of-mean force. An analytical liquid drop model is proposed to describe the pressure dependence of argon solubilization within micelles that captures the simulation solubility enhancement coefficients after fitting an effective micelle radius for each surfactant.
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Affiliation(s)
- Bin Meng
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
| | - Henry S Ashbaugh
- Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, United States
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19
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Abstract
The molecular mechanisms underlying pressure-induced protein denaturation can be analyzed based on the pressure-dependent differences in the apparent volume occupied by amino acids inside the protein and when exposed to water in an unfolded conformation. This chapter presents a volumetric analysis of the peptide group and the 20 naturally occurring amino acid side chains in the interior of the native state, the micelle-like interior of the pressure-induced denatured state, and in the unfolded conformation modeled by low-molecular analogs of proteins. The transfer of a peptide group from the protein interior to water becomes increasingly favorable as pressure increases. This observation classifies solvation of peptide groups as a major driving force in pressure-induced protein denaturation. Polar side chains do not appear to exhibit significant pressure-dependent changes in their preference for the protein interior or solvent. The transfer of nonpolar side chains from the protein interior to water becomes more unfavorable as pressure increases. An inference can be drawn that a sizeable population of nonpolar side chains remains buried inside a solvent-inaccessible core of the pressure-induced denatured state. At elevated pressures this core, owing to the absence of structural constraints, may become packed almost as tightly as the interior of the native state. The presence and partial disappearance of large intraglobular voids is another driving force facilitating pressure-induced protein denaturation. Volumetric data presented here have implications for the kinetics of protein folding and shed light on the nature of the folding transition state ensembles.
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21
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Dias CL, Chan HS. Pressure-Dependent Properties of Elementary Hydrophobic Interactions: Ramifications for Activation Properties of Protein Folding. J Phys Chem B 2014; 118:7488-7509. [DOI: 10.1021/jp501935f] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Affiliation(s)
- Cristiano L. Dias
- Department
of Physics, New Jersey Institute of Technology, University Heights, Tiernan Hall, Room 463, Newark, New Jersey 07102, United States
- Departments
of Biochemistry, Molecular Genetics, and Physics, University of Toronto, 1 King’s College Circle, Toronto, Ontario Canada M5S 1A8
| | - Hue Sun Chan
- Departments
of Biochemistry, Molecular Genetics, and Physics, University of Toronto, 1 King’s College Circle, Toronto, Ontario Canada M5S 1A8
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22
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Alvares R, Gupta S, Macdonald PM, Prosser RS. Temperature and Pressure Based NMR Studies of Detergent Micelle Phase Equilibria. J Phys Chem B 2014; 118:5698-706. [DOI: 10.1021/jp500139p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Affiliation(s)
- Rohan Alvares
- Department
of Chemistry, University of Toronto, UTM Campus, 3359 Mississauga
Road North, Mississauga, Ontario, Canada L5L 1C6
| | - Shaan Gupta
- Department
of Chemistry, University of Toronto, UTM Campus, 3359 Mississauga
Road North, Mississauga, Ontario, Canada L5L 1C6
| | - Peter M. Macdonald
- Department
of Chemistry, University of Toronto, UTM Campus, 3359 Mississauga
Road North, Mississauga, Ontario, Canada L5L 1C6
| | - R. Scott Prosser
- Department
of Chemistry, University of Toronto, UTM Campus, 3359 Mississauga
Road North, Mississauga, Ontario, Canada L5L 1C6
- Department
of Biochemistry, University of Toronto, Toronto, Ontario, Canada M5S 1A8
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23
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Huš M, Urbic T. The hydrophobic effect in a simple isotropic water-like model: Monte Carlo study. J Chem Phys 2014; 140:144904. [PMID: 24735315 DOI: 10.1063/1.4870514] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Using Monte Carlo computer simulations, we show that a simple isotropic water-like model with two characteristic lengths can reproduce the hydrophobic effect and the solvation properties of small and large non-polar solutes. Influence of temperature, pressure, and solute size on the thermodynamic properties of apolar solute solvation in a water model was systematically studied, showing two different solvation regimes. Small particles can fit into the cavities around the solvent particles, inducing additional order in the system and lowering the overall entropy. Large particles force the solvent to disrupt their network, increasing the entropy of the system. At low temperatures, the ordering effect of small solutes is very pronounced. Above the cross-over temperature, which strongly depends on the solute size, the entropy change becomes strictly positive. Pressure dependence was also investigated, showing a "cross-over pressure" where the entropy and enthalpy of solvation are the lowest. These results suggest two fundamentally different solvation mechanisms, as observed experimentally in water and computationally in various water-like models.
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Affiliation(s)
- Matej Huš
- Chair of Physical Chemistry, Department of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia
| | - Tomaz Urbic
- Chair of Physical Chemistry, Department of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia
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Graziano G. Hydrostatic pressure effect on hydrophobic hydration and pairwise hydrophobic interaction of methane. J Chem Phys 2014; 140:094503. [DOI: 10.1063/1.4866972] [Citation(s) in RCA: 15] [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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25
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Medvedev NN, Voloshin VP, Kim AV, Anikeenko AV, Geiger A. Culation of partial molar volume and its components for molecular dynamics models of dilute solutions. J STRUCT CHEM+ 2014. [DOI: 10.1134/s0022476613080088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Kim A, Medvedev N, Geiger A. Molecular dynamics study of the volumetric and hydrophobic properties of the amphiphilic molecule C8E6. J Mol Liq 2014. [DOI: 10.1016/j.molliq.2013.05.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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27
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Klähn M, Martin A, Cheong DW, Garland MV. Variation and decomposition of the partial molar volume of small gas molecules in different organic solvents derived from molecular dynamics simulations. J Chem Phys 2013; 139:244506. [PMID: 24387381 DOI: 10.1063/1.4854135] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
The partial molar volumes, V(i), of the gas solutes H2, CO, and CO2, solvated in acetone, methanol, heptane, and diethylether are determined computationally in the limit of infinite dilution and standard conditions. Solutions are described with molecular dynamics simulations in combination with the OPLS-aa force field for solvents and customized force field for solutes. V(i) is determined with the direct method, while the composition of V(i) is studied with Kirkwood-Buff integrals (KBIs). Subsequently, the amount of unoccupied space and size of pre-formed cavities in pure solvents is determined. Additionally, the shape of individual solvent cages is analyzed. Calculated V(i) deviate only 3.4 cm(3) mol(-1) (7.1%) from experimental literature values. Experimental V(i) variations across solutions are reproduced qualitatively and also quantitatively in most cases. The KBI analysis identifies differences in solute induced solvent reorganization in the immediate vicinity of H2 (<0.7 nm) and solvent reorganization up to the third solvation shell of CO and CO2 (<1.6 nm) as the origin of V(i) variations. In all solutions, larger V(i) are found in solvents that exhibit weak internal interactions, low cohesive energy density and large compressibility. Weak internal interactions facilitate solvent displacement by thermal solute movement, which enhances the size of solvent cages and thus V(i). Additionally, attractive electrostatic interactions of CO2 and the solvents, which do not depend on internal solvent interactions only, partially reversed the V(i) trends observed in H2 and CO solutions where electrostatic interactions with the solvents are absent. More empty space and larger pre-formed cavities are found in solvents with weak internal interactions, however, no evidence is found that solutes in any considered solvent are accommodated in pre-formed cavities. Individual solvent cages are found to be elongated in the negative direction of solute movement. This wake behind the moving solute is more pronounced in case of mobile H2 and in solvents with weaker internal interactions. However, deviations from a spherical solvent cage shape do not influence solute-solvent radial distribution functions after averaging over all solvent cage orientations and hence do not change V(i). Overall, the applied methodology reproduces V(i) and its variations reliably and the used V(i) decompositions identify the underlying reasons behind observed V(i) variations.
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Affiliation(s)
- Marco Klähn
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Jurong Island, Singapore 627833
| | - Alistair Martin
- School of Chemistry, The University of Edinburgh, Edinburgh, Scotland EH9 3JJ, United Kingdom
| | - Daniel W Cheong
- Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, #16-16, Connexis, Singapore 138632
| | - Marc V Garland
- Institute of Chemical and Engineering Sciences, Agency for Science, Technology and Research, 1 Pesek Road, Jurong Island, Singapore 627833
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28
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Kitevski-LeBlanc JL, Hoang J, Thach W, Larda ST, Prosser RS. 19F NMR Studies of a Desolvated Near-Native Protein Folding Intermediate. Biochemistry 2013; 52:5780-9. [DOI: 10.1021/bi4010057] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Julianne L. Kitevski-LeBlanc
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North,
Mississauga, Ontario L5L 1C6, Canada
| | - Joshua Hoang
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North,
Mississauga, Ontario L5L 1C6, Canada
| | - William Thach
- Department of Biochemistry, University of Toronto, 1 King’s College Circle,
Toronto, Ontario M5S 1A8, Canada
| | - Sacha Thierry Larda
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North,
Mississauga, Ontario L5L 1C6, Canada
| | - R. Scott Prosser
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Road North,
Mississauga, Ontario L5L 1C6, Canada
- Department of Biochemistry, University of Toronto, 1 King’s College Circle,
Toronto, Ontario M5S 1A8, Canada
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29
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Mohoric T, Urbic T, Hribar-Lee B. The application of the thermodynamic perturbation theory to study the hydrophobic hydration. J Chem Phys 2013; 139:024101. [PMID: 23862923 DOI: 10.1063/1.4812744] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The thermodynamic perturbation theory was tested against newly obtained Monte Carlo computer simulations to describe the major features of the hydrophobic effect in a simple 3D-Mercedes-Benz water model: the temperature and hydrophobe size dependence on entropy, enthalpy, and free energy of transfer of a simple hydrophobic solute into water. An excellent agreement was obtained between the theoretical and simulation results. Further, the thermodynamic perturbation theory qualitatively correctly (with respect to the experimental data) describes the solvation thermodynamics under conditions where the simulation results are difficult to obtain with good enough accuracy, e.g., at high pressures.
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Affiliation(s)
- Tomaz Mohoric
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Aškerčeva 5, SI-1000 Ljubljana, Slovenia
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30
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Ben-Naim A. Theoretical aspects of pressure and solute denaturation of proteins: A Kirkwood-buff-theory approach. J Chem Phys 2012; 137:235102. [DOI: 10.1063/1.4772463] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
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31
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Lukšič M, Urbic T, Hribar-Lee B, Dill KA. Simple model of hydrophobic hydration. J Phys Chem B 2012; 116:6177-86. [PMID: 22564051 DOI: 10.1021/jp300743a] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Water is an unusual liquid in its solvation properties. Here, we model the process of transferring a nonpolar solute into water. Our goal was to capture the physical balance between water's hydrogen bonding and van der Waals interactions in a model that is simple enough to be nearly analytical and not heavily computational. We develop a 2-dimensional Mercedes-Benz-like model of water with which we compute the free energy, enthalpy, entropy, and the heat capacity of transfer as a function of temperature, pressure, and solute size. As validation, we find that this model gives the same trends as Monte Carlo simulations of the underlying 2D model and gives qualitative agreement with experiments. The advantages of this model are that it gives simple insights and that computational time is negligible. It may provide a useful starting point for developing more efficient and more realistic 3D models of aqueous solvation.
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Affiliation(s)
- Miha Lukšič
- Faculty of Chemistry and Chemical Technology, University of Ljubljana, Slovenia
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32
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Kitevski-LeBlanc JL, Prosser RS. Current applications of 19F NMR to studies of protein structure and dynamics. PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2012; 62:1-33. [PMID: 22364614 DOI: 10.1016/j.pnmrs.2011.06.003] [Citation(s) in RCA: 210] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 07/01/2011] [Indexed: 05/20/2023]
Affiliation(s)
- Julianne L Kitevski-LeBlanc
- Department of Chemistry, University of Toronto, UTM, 3359 Mississauga Rd., North Mississauga, Ontario, Canada
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Affiliation(s)
- Franca Maria Floris
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35, 56126 Pisa, Italy.
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34
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Size dependence of cavity volume: A molecular dynamics study. Biophys Chem 2012; 161:46-9. [DOI: 10.1016/j.bpc.2011.10.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2011] [Revised: 10/14/2011] [Accepted: 10/16/2011] [Indexed: 11/18/2022]
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35
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Spooner J, Wiebe H, Boon N, Deglint E, Edwards E, Yanciw B, Patton B, Thiele L, Dance P, Weinberg N. Molecular dynamics calculation of molecular volumes and volumes of activation. Phys Chem Chem Phys 2012; 14:2264-77. [DOI: 10.1039/c2cp22949h] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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36
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Patel N, Dubins DN, Pomès R, Chalikian TV. Parsing partial molar volumes of small molecules: a molecular dynamics study. J Phys Chem B 2011; 115:4856-62. [PMID: 21466176 DOI: 10.1021/jp2012792] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
We used molecular dynamics (MD) simulations in conjunction with the Kirkwood-Buff theory to compute the partial molar volumes for a number of small solutes of various chemical natures. We repeated our computations using modified pair potentials, first, in the absence of the Coulombic term and, second, in the absence of the Coulombic and the attractive Lennard-Jones terms. Comparison of our results with experimental data and the volumetric results of Monte Carlo simulation with hard sphere potentials and scaled particle theory-based computations led us to conclude that, for small solutes, the partial molar volume computed with the Lennard-Jones potential in the absence of the Coulombic term nearly coincides with the cavity volume. On the other hand, MD simulations carried out with the pair interaction potentials containing only the repulsive Lennard-Jones term produce unrealistically large partial molar volumes of solutes that are close to their excluded volumes. Our simulation results are in good agreement with the reported schemes for parsing partial molar volume data on small solutes. In particular, our determined interaction volumes() and the thickness of the thermal volume for individual compounds are in good agreement with empirical estimates. This work is the first computational study that supports and lends credence to the practical algorithms of parsing partial molar volume data that are currently in use for molecular interpretations of volumetric data.
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Affiliation(s)
- Nisha Patel
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario, Canada
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37
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Jalan A, Ashcraft RW, West RH, Green WH. Predicting solvation energies for kinetic modeling. ACTA ACUST UNITED AC 2010. [DOI: 10.1039/b811056p] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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38
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Chalikian TV, Macgregor RB. Origins of Pressure-Induced Protein Transitions. J Mol Biol 2009; 394:834-42. [DOI: 10.1016/j.jmb.2009.10.020] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2009] [Revised: 09/29/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
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39
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Muthuselvi L, Dhathathreyan A. Understanding dynamics of myoglobin in heterogeneous aqueous environments using coupled water fractions. Adv Colloid Interface Sci 2009; 150:55-62. [PMID: 19442960 DOI: 10.1016/j.cis.2009.04.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Revised: 04/08/2009] [Accepted: 04/08/2009] [Indexed: 11/19/2022]
Abstract
This work presents an analysis of near environment of myoglobin (Mb) in different aqueous solutions (in the presence of NaCl, sucrose, trehalose, urea, and glycerol) using the coupled water fractions measured using a quartz crystal microbalance (QCM). The secondary structural features of the protein from circular dichroic (CD) spectroscopy and the coupled water fractions give important clues to the overall dynamics of the protein. Using time resolved fluorescence, these leads have been applied to understand the observed lifetime relaxations of Mb. Though the time scales of observation of coupled water and the lifetimes are very different, our study suggests that the trends in coupled water fraction seem to be good indicators for regulation of the relaxation dynamics of the protein. The relaxations generally show a triphasic distribution of time scales. The initial relaxation in the picoseconds time scale represents the local motions of coupled water followed by a slightly slower decay in hundreds of picoseconds attributable to coupled water-'quasi free' water interactions. The third nanosecond lifetime is due to changes in transitions in isomers of hydrated protein. The dynamics of coupled water in Mb with NaCl is the fastest (around 21 ps) and is slowest in glycerol (250 ps). The results strongly indicate that it is the resident times of water molecules that play a dominant role in the overall stability of protein in a particular hydrated isomer and not just always the number of such water molecules in the hydrated protein.
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Affiliation(s)
- L Muthuselvi
- Chemical Lab., CLRI (CSIR), Adyar, Chennai 600 020, India
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40
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Kinoshita M, Yoshidome T. Molecular origin of the negative heat capacity of hydrophilic hydration. J Chem Phys 2009; 130:144705. [PMID: 19368463 DOI: 10.1063/1.3112610] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The hydrophobic and hydrophilic hydrations are analyzed with the emphasis on the sign of the heat capacity of hydration (HCH). The angle-dependent integral equation theory combined with a multipolar water model is employed in the analysis. The hydration entropy (HE) is decomposed into the translational and orientational parts. It is found that the orientational part governs the temperature dependence of the HE. The orientational part is further decomposed into the solute-water pair correlation component (component 1) and the water reorganization component (component 2). For hydrophilic solutes, components 1 and 2 are negative and positive, respectively. As the temperature becomes higher, component 1 increases while component 2 decreases: They make positive and negative contributions to the HCH, respectively. The strong solute-water electrostatic attractive interactions induce the distortion of water structure near the solute and the break of hydrogen bonds. As the temperature increases, the effect of the attractive interactions becomes smaller and the distortion of water structure is reduced (i.e., more hydrogen bonds are recovered with increasing temperature). The latter effect dominates, leading to negative HCH. During the heat addition the formation of hydrogen bonds, which accompanies heat generation, occurs near the solute. Consequently, the addition of the same amount of heat leads to a larger increase in the thermal energy (or equivalently, in the temperature) than in the case of pure water. The hydrophobic hydration, which is opposite to the hydrophilic hydration in many respects, is also discussed in detail.
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Affiliation(s)
- Masahiro Kinoshita
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan.
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41
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Howard JJ, Perkyns JS, Choudhury N, Pettitt BM. An Integral Equation Study of the Hydrophobic Interaction between Graphene Plates. J Chem Theory Comput 2008; 4:1928-1939. [PMID: 19262740 DOI: 10.1021/ct8002817] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The hydrophobic association of two parallel graphene sheets is studied using the 3D-RISM HNC integral equations with several theoretical methods for the solvent distribution functions. The potential of mean force is calculated to study the effects of the aqueous solvent models and methods on the plates as a function of distance. The results of several integral equations (IE) are compared to MD simulations for the same model. The 3D-IEs are able to qualitatively reproduce the nature of the solvent effects on the potential of mean force but not quantitatively. The local minima in the potential of mean force occur at distances allowing well defined layers of solvent between the plates but are not coincident with those found in simulation of the same potential regardless of the theoretical methods tested here. The dewetting or drying transition between the plates is generally incorrectly dependent on steric effects with these methods even for very hydrophobic systems without solute-solvent attractions, in contradiction with simulation.
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Affiliation(s)
- Jesse J Howard
- Department of Chemistry, University of Houston Houston, Texas 77204-5003
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42
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Athawale MV, Sarupria S, Garde S. Enthalpy−Entropy Contributions to Salt and Osmolyte Effects on Molecular-Scale Hydrophobic Hydration and Interactions. J Phys Chem B 2008; 112:5661-70. [DOI: 10.1021/jp073485n] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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