INCORPORATION OF THE ACETYLCHOLINE-RECEPTOR DIMER FROM TORPEDO-CALIFORNICA IN A PEPTIDE SUPPORTED LIPID-MEMBRANE INVESTIGATED BY SURFACE-PLASMON AND FLUORESCENCE SPECTROSCOPY

The dimer species (M-r 580 000) of the nicotinic acetylcholine recepto r, isolated from the electric organ of Torpedo californica, was incorp orated into a thiopeptide supported lipid bilayer. The incorporation w as achieved by fusion of liposomes with reconstituted receptor onto a gold-supported thiopeptide lipid monolayer. Surface plasmon resonance spectroscopy (SPS) was used to monitor in real time the fusion process as well as the specific binding of the antagonist cu-bungarotoxin. A recently developed extension of SPS offering enhanced sensitivity and specificity, surface plasmon fluorescence spectroscopy (SPFS), was the n used to monitor subsequent binding of the monoclonal WF6 and polyclo nal antibody, respectively. The latter was fluorescence labeled with C y5. The different binding assays indicate the successful incorporation of the receptor in the lipid bilayer. (C) 1998 Elsevier Science S.A. All rights reserved.