Retained activities of some membrane proteins in stable lipid bilayers on a solid support

Highly stable lipid bilayers, composed of biologically relevant lipids such as phosphatidylcholine, phospatidylethanolamine and cholesterol, were formed on platinum surfaces. Bacteriorhodopsin isolated from purple membrane (PM) from Halobacterium halobium, cytochrome oxidase from bovine heart, acetylcholinesterase from bovine brain and the nicotinic acetylcholine receptor from Torpedo electric organ were also incorporated into these reconstituted membranes. The proteins retained their biological activities. Some of them were active several weeks after the reconstitution and after several cycles of assay washing and storage.