IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Monday Sessions
       Session BI+SS-MoA

Invited Paper BI+SS-MoA1
Simulation Studies of the Structure and Dynamics of Biological Hydration Water

Monday, October 29, 2001, 2:00 pm, Room 102

Session: Role of Water in Biological Systems
Presenter: D.J. Tobias, University of California, Irvine
Authors: D.J. Tobias, University of California, Irvine
M. Tarek, National Institute of Standards and Technology
Correspondent: Click to Email
Water, life's solvent, plays two vital roles in the function of biological macromolecules and their assemblies. One is to stabilize the specific structures that these molecules maintain in their functioning states. Another is that fast movement of water molecules promotes the flexibility of biological molecules required for their function. I will present results from molecular dynamics simulations that illustrate two peculiar aspects of water structure and dynamics near biological molecules. The first is the structure of water on the surface of lipid membranes. I will show that the first layer of water coating the membrane surface is strongly influenced by the lipid molecules, and that the anisotropic solvation of the lipid polar groups profoundly affects the polarity of the membrane/water interface. The second is the motion of water molecules on the surface of proteins. Below a threshold level of hydration and thermal energy, proteins exist in an inactive, glassy state. I will show that the transition from the glassy state to the functioning state requires relaxation of the protein-water hydrogen bond network. Finally, I will discuss some of the anomalous dynamical properties of protein hydration water, drawing analogies with supercooled and confined water.