Membrane channel and pore proteins are nanometer-sized pumps and valves, transporting ions and molecules selectively based on size, charge, or type. Some of these proteins actuate in response to an applied voltage, a property which immediately suggests possible device applications. The short functional lifetimes of proteins in lipids necessitates the use of biocompatible polymers which mimic the natural environment of the protein sufficiently that function is retained. We have genetically engineered a voltage-gatable pore protein and inserted it into monolayer planar membranes of amphiphilic block copolymers. I will present our recent work in engineering this hybrid protein/polymer system. We have characterized the porin and protein/polymer complex at the nanometer and micrometer length scales. I will show the results of electrical and analyte transport experiments demonstrating the gating ability and the degree of protein orientation within the membrane. I will discuss the implications of these experiments and prospects for devices functionalized with nanoscale valves or polymers having controllable porosity. Our future work will center on increasing robustness and device incorporation of these hybrid polymer as well as exploration and expansion of the palette of membrane proteins available: proteins which include voltage, temperature, mechanical, and ligand-sensitive sensors, in addition to transporters and pumps.
UCLA Department of Bioengineering
7523 Boelter Hall
Los Angeles, CA 90095-1600 USA
Phone: (310) 825-4451 Fax: (310) 794-5956