Potential of mean forces of solutes in water by modified solvent-accessible surface method

We propose an empirical method for evaluating the potential of mean force (p.m.f.) of solutes in water by modifying the solvent-accessible-surface (SAS) method described by Eisenberg et al. In addition to the SAS energy, the energy required to generate an excluded volume between adjacent solute molecules and the energy contribution due to coulomb interactions are accounted for in the proposed method. The proposed method was examined on the p.m.fs of methane-methane in water and successfully reproduced the p.m.fs. This method is basically applicable to general molecular interactions, such as protein-protein interactions in water.