Reconstitution of acetylcholine receptor function in lipid vesicles of defined composition.

The effect of specific lipids on the functional properties of the acetylcholine receptor were examined in reconstituted membranes prepared from purified Torpedo californica acetylcholine receptor and various defined lipids. Cholesterol and negatively charged lipids greatly enhanced the ion influx response of the vesicles as measured by the effect of a receptor agonist on cation translocation across the vesicles. Part of the lipid-dependent effects could be attributed to alterations in the average size of the vesicles. All lipid mixtures used permitted complete incorporation of receptor and retention of ligand binding properties. Quantitative differences in ion flux properties suggest a modulating role for specific lipids in acetylcholine receptor function.