Pressure Dependence of the Dynamic Crossover Temperatures in Protein and its Hydration Water
Abstract
Recently we have shown experimental evidence for a fragile-to-strong dynamic crossover (FSC) phenomenon in hydration water around a globular protein (lysozyme) at ambient pressure. In this letter we show that when applying pressure to the protein-water system, the FSC crossover temperatures in hydration water of lysozyme tracks the similar Widom line emanating from the existence of a liquid-liquid critical point in a 1-D confined water (in MCM-41-S). The mean squared displacements (MSD) of hydrogen atoms in lysozyme and in its hydration water show a sudden change of slopes at the same characteristic temperature, which decreases with an increasing pressure. These results taken together give support of the idea that the dynamic crossover (or so-called glass transition) of the protein is a function of both temperature and pressure, following the FSC of its hydration water.
Keywords
Cite
@article{arxiv.0810.1228,
title = {Pressure Dependence of the Dynamic Crossover Temperatures in Protein and its Hydration Water},
author = {Xiang-qiang Chu and Antonio Faraone and Chansoo Kim and Emiliano Fratini and Piero Baglioni and Juscelino B. Leao and Sow-Hsin Chen},
journal= {arXiv preprint arXiv:0810.1228},
year = {2008}
}
Comments
4 pages, 4 figures