Professor Nancy L. Thompson, Department of Chemistry, University of North Carolina at Chapel Hill
4 PM, Thursday, October 3, 1996
Room 101, Olin Physical Laboratory
The equilibrium binding, kinetics, diffusion, and self-association of proteins at membrane/solution interfaces deviate substantially from these processes in bulk solution. To measure these behaviors, model biological membranes, constructed on planar fused silica surfaces from Langmuir-Blodgett films or by adsorption of phospholipid vesicles from adjacent solutions, are examined by quantitative fluorescence microscopy under evanescent wave illumination(total internal reflection). Steady-state, surface-associated fluorescence can be used to examine the thermodynamic properties of proteins located within 90 nm of the surface. Fluorescence photobleaching recovery measures membrane binding kinetics;fluorescence pattern photobleaching recovery measures translational diffusion coefficients. Polarized evanescent illumination tells the orientation distribution of adsorbed fluorophores. Finally, fluorescence correlation spectroscopy can be used to study the dimerization of membrane-associated proteins.