Hydrolysis of benzoylcholine derivatives by cholinesterase in serum

Abstract

A series of derivatives of benzoylcholine were prepared with substituents in the benzene ring, and the rate of hydrolysis of these compounds with cholinesterase of horse serum detd. It is concluded that the innate reactivity of the ester linkage is as important as the "goodness of fit" between enzyme and substrate in determining the rate of reaction. Solution of the Arrhenius equation suggests that greater energy of activation is required when the carbonyl group is the more activated. This condition could be fulfilled by supposing a positive or partially positive charge on the enzyme to react with the carbonyl oxygen of the ester to form an intermediate compound.