Transmembrane protein electrophoresis in suspended phospholipid bilayers

ANYL 377

M. Scott Long, mslong@email.arizona.edu and Mary J. Wirth, mwirth@email.arizona.edu. Department of Chemistry, University of Arizona, 1306 E. University Blvd., Room 104, Tucson, AZ 85721
For many assays of transmembrane protein function, it is required to isolate the protein from others in the cell membrane. Unfortunately, efficient electrophoresis in solution is often incompatible with retention of functional transmembrane protein activity, and affinity chromatography lacks the multiplexing capability of electrophoresis. An electrophoresis technique is needed that is compatible with retention of transmembrane protein structure and function. We report electrophoresis of functional transmembrane proteins in suspended phospholipid bilayers. A planar phospholipid bilayer was suspended across a monolayer of silica nanoparticles. Planarity of the phospholipid bilayer was enhanced through the inclusion of cholesterol without sacrificing lateral mobility. The human delta-opioid receptor, a G protein-coupled receptor, was electrophoretically mobile in the phospholipid bilayer with a significant protein mobile fraction. Such constructs will enable separations of transmembrane proteins while simultaneously probing their function.