April 25, Thu 2013
3:00 pm, MRB 200 Conference Room
Dr. Alex Sodt
Laboratory of Computational Biology, NIH
Modeling how membrane mechanical properties couple to protein function
Simulations indicate that substantial local tensions are present in a planar lipid bilayer. For example, there is an effective positive surface tension near the polar/apolar interface acting to shrink the bilayer area (equivalent to the tension of an oil/water interface). This tension is balanced by an effective negative surface tension in the tail region where area expansion would allow greater conformational sampling. The mechanical properties of a lipid bilayer (that is, how much energy it takes to bend and deform the bilayer) are a direct consequence of this stress. Furthermore, membrane-active biomolecules must function in this environment, influencing and being influenced by the mechanical stress. Knowledge of how lipid chemistry, protein conformation, and membrane deformation are coupled will have far-reaching consequences for the analysis of protein-mediated membrane remodeling and lipid-regulated transmembrane signaling. In this work, new simulation methodologies for studying the coupling of membrane curvature to protein conformation will be presented and compared to the relatively sparse amount of experimental data available.