Test of cold denaturation mechanism for proteins as a function of water's structure

TL;DR

This study tests a proposed mechanism for protein cold denaturation related to water structure changes using atomistic simulations, finding that denaturation occurs at high-density water conditions where hydrogen bonding decreases.

Contribution

It provides computational evidence supporting the water-structure-based mechanism for protein cold denaturation, linking it to high-density water states.

Findings

Cold denaturation occurs at high-density water conditions.

Unfolded proteins correlate with decreased hydrogen bonds.

Simulation results align with the proposed mechanism.

Abstract

In a recent paper [PRL 91, 138103 (2003)] a new mechanism to explain the cold denaturation of proteins, based on the loss of local low-density water structure, has been proposed. In the present paper this mechanism is tested by means of full atom numerical simulations. In good agreement with this proposal, cold denaturation resulting in the unfolded state was found at the High Density Liquid (HDL) state of water, at which the amount of open tetragonal hydrogen bonds decreases at cooling.