Coupling nonpolar and polar solvation free energies in implicit solvent models

Abstract

Recent studies on the solvation of atomistic and nanoscale solutes indicate that a strong coupling exists between the hydrophobic, dispersion, and electrostatic contributions to the solvation free energy, a facet not considered in current implicit solvent models. We suggest a theoretical formalism which accounts for coupling by minimizing the Gibbs free energy of the solvent with respect to a solvent volume exclusion function. The resulting differential equation is similar to the Laplace-Young equation for the geometrical description of capillary interfaces, but is extended to microscopic scales by explicitly considering curvature corrections as well as dispersion and electrostatic contributions. Unlike existing implicit solvent approaches, the solvent accessible surface is an output of our model. The presented formalism is illustrated on spherically or cylindrically symmetrical systems of neutral or charged solutes on different length scales. The results are in agreement with computer simulations and, most importantly, demonstrate that our method captures the strong sensitivity of solvent expulsion and dewetting to the particular form of the solvent-solute interactions.

accpted in J. Chem. Phys

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Cited by in corpus (10)

• Application of the level-set method to the implicit solvation of nonpolar molecules
• Dewetting-controlled binding of ligands to hydrophobic pockets
• Convergence of Phase-Field Free Energy and Boundary Force for Molecular Solvation
• Interface dynamics of microscopic cavities in water
• Variational implicit-solvent predictions of the dry-wet transition pathways for ligand-receptor binding and unbinding kinetics
• How interface geometry dictates water's thermodynamic signature in hydrophobic association
• The Calculus of Boundary Variations and the Dielectric Boundary Force in the Poisson-Boltzmann Theory for Molecular Solvation
• A Compact Coupling Interface Method with Accurate Gradient Approximation for Elliptic Interface Problems
• Binary Level Set Method for Variational Implicit Solvation Model
• Explicit-Solute Implicit-Solvent Molecular Simulation with Binary Level-Set, Adaptive-Mobility, and GPU