Acetylcholine Receptor: Covalent Attachment of Depolarizing Groups at the Active Site

Abstract
Following reduction of the acetylcholine receptor in the electroplax with dithiothreitol, the quaternary ammonium compounds bromoacetylcholine bromide and the p -nitrophenyl ester of ( p -carboxyphenyl) trimethylammonium iodide react near the active site probably with a sulfhydryl group. The covalently attached quaternary ammonium moieties additionally interact with the active site noncovalently to activate the receptor and cause depolarization of the cell.