Abstract

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.