Molecular Pharmacology, Vol 6, 266-272, Copyright © 1970 by the American Society for Pharmacology and Experimental Therapeutics

The Effect of Fluoride on the Reaction of Acetylcholinesterase with Carbamates

¹ Department of Biochemistry, College of Physicians and Surgeons, Columbia University, New York, New York 10032, and Department of Chemistry, University of Colorado, Boulder, Colorado 80302

The effect of fluoride on the rates of carbamylation and decarbamylation of acetylcholinesterase was studied using dimethylcarbamyl fluoride, dimethylcarbamylcholine, and monomethylcarbamylcholine as carbamylating agents. In all cases concentrations of fluoride between 10^-4 M and 10^-3 M, which markedly decreased the rate of hydrolysis of acetylcholine, also markedly decreased the rate of carbamylation. On the other hand, concentrations of fluoride as high as 0.1 M failed to affect the rate of decarbamylation of the dimethylcarbamyl-enzyme and the monomethylcarbamyl-enzyme. Fluoride was also without effect on the nucleophilic decarbamylation or reactivation caused by hydroxylamine and choline.