LIPID MODULATION OF NICOTINIC ACETYLCHOLINE-RECEPTOR FUNCTION - THE ROLE OF MEMBRANE LIPID-COMPOSITION AND FLUIDITY

The effects of membrane lipid composition and fluidity on AChR ion cha nnel function were studied after reconstituting the receptor with sphi ngomyelin, phosphatidylcholines with different degrees of unsaturation , or different neutral lipids. AChR ion flux activity was shown to be retained in some membranes of both high and low fluidity, as measured by the steady-state anisotropy of the membrane probes diphenylhexatrie ne and trimethylammonium diphenylhexatriene. The results suggest that lipid composition is more important than bulk membrane fluidity in det ermining AChR ion channel function.