Dispersion Terms and Analysis of Size- Charge Dependence in an Enhanced Poisson Boltzmann Approach

TL;DR

This paper enhances the Poisson-Boltzmann continuum solvation model by incorporating dispersion effects, enabling accurate solvation free energy estimates for proteins and chemicals, with parameters fitted to experimental and quantum data.

Contribution

It introduces a dispersion-inclusive Poisson-Boltzmann approach with a flexible framework, validated against experimental and quantum calculations, and applied to proteins to study size and charge effects.

Findings

Accurately estimates solvation free energies for chemicals and proteins.

Demonstrates the model's flexibility and general applicability.

Provides insights into size and charge dependence in protein solvation.

Abstract

We implement a well-established concept to consider dispersion effects within a Poisson-Boltzmann approach of continuum solvation of proteins. The theoretical framework is particularly suited for boundary element methods. Free parameters are determined by comparison to experimental data as well as high-level quantum mechanical reference calculations. The method is general and can be easily extended in several directions. The model is tested on various chemical substances and found to yield good-quality estimates of the solvation free energy without obvious indication of any introduced bias. Once optimized, the model is applied to a series of proteins, and factors such as protein size or partial charge assignments are studied.