TY - JOUR
T1 - Local density profiles are coupled to solute size and attractive potential for nanoscopic hydrophobic solutes
AU - Choudhury, N.
AU - Pettitt, B. Montgomery
N1 - Funding Information:
We gratefully acknowledge NIH, the R.A. Welch foundation, and TIMES, funded by NASA Cooperative Agreement No. NC-1-02038 for partial financial support of this work. The computations were performed in part using the NSF meta center facilities and the Molecular Science Computing Facility in the W.R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by DOE’s Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory, operated for DOE by Battelle.
PY - 2005/5/15
Y1 - 2005/5/15
N2 - We employ constant pressure molecular dynamics simulations to investigate the effects of solute size and solute-water dispersion interactions on the solvation behavior of nanoscopic hydrophobic model solutes in water at normal temperature and pressure. The hydration behavior around a single planar atomic model solute as well as a pair of such solutes have been considered. The hydration water structure of a model nanoscopic solute with standard Lennard-Jones interaction is shown to be significantly different from that of their purely repulsive analogues. The density of water in the first solvation shell of a Lennard-Jones solute is much higher than that of bulk water and it remains almost unchanged with the increase of the solute dimensions from one to a few nanometers. On the other hand, for a purely repulsive analogue of the above model, solute hydration behavior shows a marked solute size dependence. The contact density of water in this case decreases with the increasing dimension of the solute. We also demonstrate the effect of solute-solvent attraction on the cavity formation in the inter solute region between two solutes with an inter solute separation of 6.8 Å, corresponding to the first solvent separated minimum in the free energy profile as obtained in our earlier work.
AB - We employ constant pressure molecular dynamics simulations to investigate the effects of solute size and solute-water dispersion interactions on the solvation behavior of nanoscopic hydrophobic model solutes in water at normal temperature and pressure. The hydration behavior around a single planar atomic model solute as well as a pair of such solutes have been considered. The hydration water structure of a model nanoscopic solute with standard Lennard-Jones interaction is shown to be significantly different from that of their purely repulsive analogues. The density of water in the first solvation shell of a Lennard-Jones solute is much higher than that of bulk water and it remains almost unchanged with the increase of the solute dimensions from one to a few nanometers. On the other hand, for a purely repulsive analogue of the above model, solute hydration behavior shows a marked solute size dependence. The contact density of water in this case decreases with the increasing dimension of the solute. We also demonstrate the effect of solute-solvent attraction on the cavity formation in the inter solute region between two solutes with an inter solute separation of 6.8 Å, corresponding to the first solvent separated minimum in the free energy profile as obtained in our earlier work.
KW - Dewetting
KW - Hydrophobic hydration
KW - NPT molecular dynamics simulation
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U2 - 10.1080/08927020500035457
DO - 10.1080/08927020500035457
M3 - Article
AN - SCOPUS:22144498084
SN - 0892-7022
VL - 31
SP - 457
EP - 463
JO - Molecular Simulation
JF - Molecular Simulation
IS - 6-7
ER -