CARBAMYLCHOLINE-INDUCED RAPID CATION EFFLUX FROM RECONSTITUTED MEMBRANE-VESICLES CONTAINING PURIFIED ACETYLCHOLINE-RECEPTOR

Membrane preparations containing essentially only the four polypeptides considered to constitute the acetylcholine receptor are purified from Torpedo californica electroplax. Treatment of these membranes with 2% ( w v aqueous sodium cholate followed by removal of all insoluble matter results in a solubilized purified receptor preparation that can be reassociated with phospholipids during dialysis to remove the detergent. Such reconstituted receptor is shown to retain the capability of translocating 22Na+ across the membrane in response to carbamylcholine binding in a highly reproducible manner. The dose response for this effect is similar to that observed for the original electroplax membrane preparation and the carbamylcholine induced signal is completely blocked by α-bungarotoxin. © 1979.