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Evaluation of the influence of the internal aqueous solvent structure on electrostatic interactions at the protein‐solvent interface by nonlocal continuum electrostatic approach
Author(s) -
Rubinstein Alexander,
Sherman Simon
Publication year - 2007
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.20808
Subject(s) - dielectric , chemistry , solvent , electrostatics , dipole , aqueous solution , chemical physics , polar , permittivity , solvent effects , debye length , debye , polarization (electrochemistry) , solvation shell , relative permittivity , computational chemistry , solvation , materials science , organic chemistry , ion , physics , quantum mechanics , optoelectronics
The dielectric properties of the polar solvent on the protein‐solvent interface at small intercharge distances are still poorly explored. To deconvolute this problem and to evaluate the pair‐wise electrostatic interaction (PEI) energies of the point charges located at the protein‐solvent interface we used a nonlocal (NL) electrostatic approach along with a static NL dielectric response function of water. The influence of the aqueous solvent microstructure (determined by a strong nonelectrostatic correlation effect between water dipoles within the orientational Debye polarization mode) on electrostatic interactions at the interface was studied in our work. It was shown that the PEI energies can be significantly higher than the energies evaluated by the classical (local) consideration, treating water molecules as belonging to the bulk solvent with a high dielectric constant. Our analysis points to the existence of a rather extended, effective low‐dielectric interfacial water shell on the protein surface. The main dielectric properties of this shell (effective thickness together with distance‐ and orientation‐dependent dielectric permittivity function) were evaluated. The dramatic role of this shell was demonstrated when estimating the protein association rate constants. © 2007 Wiley Periodicals, Inc. Biopolymers 87: 149–164, 2007. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com