Planar and vesicular membranes formed by archaebacteria ether lipids will be characterized and assessed as potential biomimetic membranes. Archaebacteria are a recently discovered life-form living in extreme environments including pH values less than 2.0 or greater than 9.0 in saturated salt solutions at temperatures greater than the normal boiling point of water. Polar lipids isolated from plasma membranes of the archaebacteria contain an ether linkage, rather than the ester linkages usually found in membrane lipids. Ester linkages are less susceptible to oxidation and hydrolysis; thus, more stable membrane mimetics can be constructed from them. Since the ether lipids contain polar groups like those in normal cell membranes, but are more stable than normal cell lipids, they seem to be ideal candidates for constructing synthetic analogues of cell membranes. The project will attempt: (1) to construct ultra thin separation membranes with outstanding selectivity and fluxes and (2) to make electrode coating to immobilize enzymes that catalyze hydroxylation of lipophiles.