Attempts to mimic docking processes of the immune system: recognition-induced formation of protein multilayers

The assemblage of protein multilayers induced by molecular recognition, as seen, for example, in the immune cascade, has been mimicked by using streptavidin as a docking matrix. For these experiments, this protein matrix was organized on liposomes, monolayers at the air-water interface, and self-assembled layers on gold, all three containing biotin lipids. The docking of streptavidin to biotin at liposomal surfaces was confirmed by circular dichroism. Mixed double and triple layers of streptavidin, concanavalin A, antibody Fab fragments, and hormones are prepared at the air-water interface and on gold surfaces and were characterized by fluorescence microscopy and plasmon spectroscopy. With the use of biotin analogs that have lower binding constants it has been possible to achieve multiple formation and competitive replacement of the oriented protein assemblages.