Inhibition of acetylcholine storage by acetylcholine analogs in vitro

GA Rogers and SM Parsons

Department of Chemistry, University of California, Santa Barbara 93106.

Forty-five acetylcholine (AcCh) analogs were chemically synthesized and characterized. They and two commercially available analogs were tested for the ability to inhibit active transport of AcCh by synaptic vesicles purified from the electric organ of Torpedo californica. A range of potencies greater than 4 orders of magnitude was found. A quaternary nitrogen and the presence of the carbonyl group are important to potency. The addition of hydrophobic groups to both ends of isonipecotic acid yielded the most potent analogs, which exhibited a nearly 1000-fold increase in potency relative to AcCh. The probable conformation of AcCh bound by the transporter has been deduced and confirmed by the synthesis of a potent rigid analog based on 2-amino-9- fluorenone. A potent analog was shown to be a competitive inhibitor with respect to AcCh, thus confirming that its site of action is the transporter active site. The structure-activity data clearly distinguish the binding site for AcCh from the site for vesamicol [(--)- (trans)-2-(4-phenylpiperidino)cyclohexanol], which is a noncompetitive inhibitor.

Volume 36, Issue 2, pp. 333-341, 08/01/1989
Copyright © 1989 by American Society for Pharmacology and Experimental Therapeutics

This article has been cited by other articles:

				S. M. PARSONS Transport mechanisms in acetylcholine and monoamine storage FASEB J, December 1, 2000; 14(15): 2423 - 2434. [Abstract] [Full Text]