Functionality and Protein-Water Interactions

TL;DR

This paper investigates how water influences protein secondary structures and introduces a new perspective on water-induced order, offering insights into protein dynamics and evaluating hydrophobicity scales.

Contribution

It reveals water-induced medium-range order in protein secondary elements and assesses the reliability of hydrophobicity scales, advancing understanding of protein-water interactions.

Findings

Water-induced medium-range order varies across secondary elements.

Hydrophobicity scales differ in reliability for predicting protein behavior.

Water interactions can complement or resemble structural order.

Abstract

The structures of proteins exhibit secondary elements composed of helices and loops. Comparison of several water-only hydrophobicity scales with the functionalities of two repeat proteins shows that these secondary elements possess water-induced medium-range order that is sometimes similar, but can also be complementary, to structural order. Study of these hitherto "phantom" order parameters promises far-reaching incremental improvements in the theory of protein dynamics. A by-product of the theory is an independent evaluation of the reliability of different hydrophobicity scales.