. Order parameter defining liquid-liquid transition in water

GRIGERA J. R.; MCCARTHY A.N.

Dallas, Texas

Congreso; APS March Meeting; 2011

Amrtican Physical Society

Cold denaturation of proteins and water J. Raul Grigera Institute of Physics of Liquids and Biological Systems (IFLYSIB) and Department of Biology, Faculty of Science, University of La Plata. While thermal denaturation of proteins has been the subject of extensive studies, the process of cold denaturation is much less well understood. A key ingredient of cold denaturation is the effect of pressure on the stability of proteins. In a protein solution at room temperature, pressures over 2 kbar are enough to begin the denaturation process. However, and seemingly paradoxically, the application of a certain amount of pressure can also serve as a means of enhancing protein stability to thermal denaturation. This behavior can be explained taking into account changes in water structure, in which the pressure changes the balance between low and high density structural components. We will present some examples of pressure denaturation of proteins from molecular dynamics simulation and propose a simple method to determine the crossover between low and high density components of water, connected with the cold denaturation.