The Ion Flux Mediated by Acetylcholine Receptor

Abstract

Acetylcholine induces both a fast conformational change of acetylcholine rece ptor that results in the opening of ion-conducting channels through the membrane, and a slow conformational change that results in an inactivation of the receptor (desensitization). The relationship between the binding of the agonist to the receptor and the receptor-mediated ion flux or the desensitization has been studied by three kinds of experiments; 1) ion flux measurements with a quench flow method, 2) fluorescence measurements with a stopped flow method and 3) α-toxin binding to the receptor. Several models are summarized and discussed.