Molecular solute-solvent interactions are a key determinant of physical processes such as solubility, drug binding, and the conformational stability of macromolecules. However, accurately computing the thermodynamics of interactions, including decomposition in energy, entropy, and their spatial location, remains a challenge. The 3D reference interaction site model (3D-RISM) theory of molecular solvation is an attractive approach as it is able to rapidly calculate equilibrium solvent density and thermodynamic distributions, including energy and entropy. First, we will demonstrate the ability of 3D-RISM to decompose solvation free energy in polar/nonpolar and energy/entropy.  Using several large data sets of charged and neutral small molecules in aqueous and non-polar solvents, 3D-RISM achieves the same level of accuracy as all-atom molecular simulation. Then, we will discuss the spatial decomposition solvation thermodynamics to identify essential water molecules in the protein factor Xa. Here we find good agreement between 3D-RISM and the grid inhomogeneous solvation theory (GIST) using explicit solvent for protein-water energies, but find discrepancies for water re-organization contributions to the energy and entropy. <br/>

Solvation energy and entropy from 3D-RISM

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.