Molecular dynamics study of anysotropic solvation of membrane bound proteins

PHYS 474

Sui Shen, Madhusoodanan Mottamal,, and Goran Krilov, Department of Chemistry, Boston College, 2609 Beacon Street, Chestnut Hill, MA 02467
Solvation has profound effects on the biological activity of proteins. While the effects of aqueous solvent on the structure and dynamics of proteins have been widely studied, a dearth of structural data leaves our understanding the anysotropic solvation environment in cell membranes much less complete. In this contribution, we use molecular dynamics simulations to study the solvation thermodynamics of the c-subunit of ATP synthase in two solvent environments: methanol/chloroform mixture, a membrane mimetic widely used in NMR structural studies, as well as the lipid bilayer. We analyze the protein and solvent structure, as well as solvent-protein interactions as a function of solvent composition to identify key contributions to protein stabilization. We furthermore quantify the degree of similarity between protein structures observed in the two environments. Finally, we show protein-induced local phase separation to be the primary mechanism through which the aforementioned isotropic mixtures mimic the anisotropic environment of the membrane.

Poster Session
7:30 PM-10:00 PM, Wednesday, 13 September 2006 Moscone Center -- Hall D, Poster

8:00 PM-10:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Sci-Mix

Division of Physical Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006