THIOPEPTIDE-SUPPORTED LIPID LAYERS ON SOLID SUBSTRATES

The sequential layer-by-layer formation of peptide-supported bimolecul ar lipid membranes at solid supports is described. In the first step, thiol-derivatized peptide sequences of 5 and 7 amino acids are assembl ed on a Au substrate. After activation of their COOH-terminus phosphol ipid molecules (DMPE) are covalently attached via an amid bond to form a tethered monolayer on the Au electrode. The different preparation s teps are analyzed by Fourier transform IR, X-ray reflectometry, and su rface plasmon spectroscopy. The latter technique is then also used to on-line monitor at the solid/solution interface the formation of a bil ayer by fusion of vesicles prepared from a fluid Lipid mixture with an d without reconstituted proteins. The obtained thicknesses and capacit ance values are compatible with the tethered bilayer model and point t o an incorporation of ATPase into these membrane matrices.