IUVSTA 15th International Vacuum Congress (IVC-15), AVS 48th International Symposium (AVS-48), 11th International Conference on Solid Surfaces (ICSS-11)
    Biomaterials Friday Sessions
       Session BI-FrM

Paper BI-FrM11
Crystalline Bacterial S-Layer Proteins: A New Supporting Structure to Separate and Stabilize Lipid Membranes

Friday, November 2, 2001, 11:40 am, Room 102

Session: Biosensors
Presenter: B. Schuster, Universitaet fuer Bodenkultur Wien, Austria
Authors: B. Schuster, Universitaet fuer Bodenkultur Wien, Austria
P.C. Gufler, Universitaet fuer Bodenkultur Wien, Austria
D. Pum, Universitaet fuer Bodenkultur Wien, Austria
U.B. Sleytr, Universitaet fuer Bodenkultur Wien, Austria
Correspondent: Click to Email
A key component in the combination of membrane-associated molecular recognition mechanisms with inorganic surfaces is an ultrathin layer separating the lipid membrane and the solid surface. The demands on this layer are manifold as it should both, stabilize and maintain the fluidity and structural properties of the lipid membrane. This is an essential feature providing an environment for reconstitution and immobilization of membrane proteins under non-denaturing conditions. One promising strategy is the application of bacterial cell surface layers (S-layers) to support (bilayer) lipid membranes (BLMs). S-layer proteins are the simplest self-assembly systems that produce crystalline, nanometer-thick, isoporous lattices with well-defined topographical and physico-chemical properties. S-layer proteins have been recrystallized on solid supports like gold or silicon wafers, or deposited on porous polymer filters. Attached BLMs exhibit an increased fluidity compared to dextran- or silane-supported BLMs and the stability is significantly enhanced. By contrast with the less stable BLM on polymer filters, successful reconstitution of staphylococcal alpha-hemolysin was observed with BLMs separated by an S-layer from the porous support. The unitary conductance of a hemolysin pore was found to be similar reconstituted in S-layer supported BLMs on porous supports and in common folded BLMs. As an alternative to soft polymer cushions, to hybrid or tethered lipid membranes, S-layer supported lipid membranes provide a biomimetic, water-containing environment for transmembrane proteins. Furthermore, composite S-layer/lipid membranes in combination with new sensor technology might play an important role in the development of biosensors.