S-layer stabilized solid supported lipid bilayers

This work describes composite structures composed of lipid bilayer or tetraetherlipid monolayer films attached to solid supports with associated crystalline bacterial cell surface layers (S-layers). The bilayer system was established by making use of the strong chemisorption of a first monolayer of thiolipids (1-octadecanethiol or 1,2-dimyristoyl-sn-glycero 3-phosphothioethanol) on gold and attaching a second monolayer of 1,2-dipalmitoyl-sn-3-phosphatidylethanolamine by the Langmuir Schaefer technique. The tetraetherlipid monolayer was composed of Glycerol-dialkyl-nonitol tetraetherlipid (GDNT). The monolayer of GDNT exhibits the thickness of a bilayer with hydrophilic headgroups on both sides and a hydrophobic inner part. Isolated S-layer protein from Bacillus sphaericus CCM2177, which was injected into the subphase of an LB-trough, recrystallized into a coherent monolayer at the solid supported phospholipid bilayer and at the tetraetherlipid monolayer. The composite lipid/S-layer structures were stable enough to allow lifting from the air-water interface, rinsing in water, and transfer into a scanning force microscope. (C) 1997 Academic Press.