Invited Paper BI+AS+NS-ThA1
Creating and Probing Model Biological Membranes

Thursday, October 18, 2007, 2:00 pm, Room 609

During the past few years, our lab has developed a wide range of methods for patterning lipid bilayers on solid supports.¹ These 2D fluids are interesting both as a model for biological membranes and as a physical system with unusual properties. Methods have been developed for controlling the composition of patterned membrane corrals by variations on microcontact printing and microfluidics. Charged components can be moved around within these fluid surfaces by a form of 2D electrophoresis. The planar geometry of supported bilayer systems is ideal for high resolution imaging methods. The lateral (x-y) composition of membranes can be analyzed by high spatial resolution secondary ion mass spectrometry (SIMS) using the NanoSIMS 50 (Cameca) at the Livermore National Laboratory. Results will be described for simple membrane compositions² and phase separated domains³ suggesting the potential of this method for the analysis of membrane organization in complex membranes. Extensions of this approach to more complex systems including membrane-associated proteins will be described. If time permits, a complimentary optical imaging method offering sub-nm resolution in the z-direction (perpendicular to the membrane surface) will be described in the context of imaging conformational changes in membrane proteins.

¹J. T. Groves and S. G. Boxer, Accounts of Chemical Research, 35, 149-157 (2002).
²C. Galli Marxer, M. L. Kraft, P. K. Weber, I. D. Hutcheon and S. G. Boxer, Biophysical Journal, 88, 2965-2975 (2005).
³M. L. Kraft, P. K. Weber, M. L. Longo, I. D. Hutcheon, S. G. Boxer, Science, 313, 1948-1951 (2006).