Hydrophobicity Scaling of Aqueous Interfaces by an Electrostatic Mapping

TL;DR

This paper introduces a new electrostatic mapping technique to classify and understand the hydrophobic and hydrophilic regions of complex molecular interfaces, improving predictions of water-mediated interactions.

Contribution

The novel electrostatics-based mapping method captures long-wavelength water responses, distinguishing hydrophobic and hydrophilic regions and their polarization effects.

Findings

Differentiates hydrophobic and hydrophilic surface regions

Identifies opposing polarization directions in hydrophilic areas

Enhances prediction of water-mediated interactions

Abstract

An understanding of the hydrophobicity of complex heterogeneous molecular assemblies is crucial to characterize and predict interactions between biomolecules. As such, uncovering the subtleties of assembly processes hinges on an accurate classification of the relevant interfaces involved, and much effort has been spent on developing so-called "hydrophobicity maps." In this work, we introduce a novel electrostatics-based mapping of aqueous interfaces that focuses on the collective, long-wavelength electrostatic response of water to the presence of nearby surfaces. In addition to distinguishing between hydrophobic and hydrophilic regions of heterogeneous surfaces, this electrostatic mapping can also differentiate between hydrophilic regions that polarize nearby waters in opposing directions. We therefore expect this approach to find use in predicting the location of possible water-mediated hydrophilic interactions, in addition to the more commonly emphasized hydrophobic interactions that can also be of significant importance.