Professor Bob Eisenberg
Molecular Biophysics and Physiology
Rush University Medical Center
Chicago, IL

Monday, January 31, 2005
3:00 pm (CT)
3269 Beckman Institute

Abstract

Selectivity is one of the most important features of channels and proteins: calcium channels, for example, allow only calcium to flow even when sodium is present in great excess. Understanding selectivity is difficult even when a protein structure is available: structural information---no matter how precise---does not specify the energies, entropies, and friction coefficients that determine selectivity. Molecular dynamics is problematic for design purposes unless it is calibrated to give correct thermodynamic properties--electrostatic energies, entropies, and activity coefficients. Calibration is a daunting (but possible!) task. We use reduced physical models that account for the energies of crowded charge and show that such models allow insight into the origin of selectivity and provide designs for calcium channels. One of those designs has been implemented and works as expected-- reasonably but not perfectly well.

Tea and coffee will be served in R3151 Beckman Institute at 2:15pm.