Physics Colloquium, May 18, 2004

Patterned bilayers and tethered vesicles: tools for membrane biology

Steven G. Boxer

Department of Chemistry, Stanford University

During the past few years, our lab has developed a wide range of methods for patterning lipid bilayers on solid supports [Accts. Chem. Res. 35, 149 (2002)]. 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. Molecules can be moved around within these fluid surfaces by a form of 2D electrophoresis. These methods have been recently been combined to pattern and manipulate vesicles that are tethered to fluid bilayers by short complimentary DNA sequences. Once tethered, vesicles are laterally mobile in the plane of the supported bilayer. Arrays of corrals can be used to tether and sort vesicles displaying the complimentary sequence, and different vesicles can have different contents, lipid composition and/or membrane-associated proteins encoded by the corresponding oligonucleotide sequence. Because the vesicles are laterally mobile, individual vesicle-vesicle interactions, mediated by different components on the vesicle surface or in solution, can be observed directly. Tools that allow vesicle purification and 2D mixing will be described.

3.30 p.m., Smith Laboratory, Room 1005

Refreshments served in Smith 1094 at 3:00 p.m.