Abstract

The hydrolysis of acetylcholine by horse serum cholinesterase has been measured by nuclear magnetic resonance spectroscopy. The reaction rate was estimated from the formation of free acetate, whose characteristic frequency of absorption differs from that of the acetate moiety of acetylcholine. From the decay of the acetate signal of acetylcholine and/or the formation of the sodium acetate signal in sodium phosphate buffer, it is possible to follow the rate of the reaction. The calculated K_m for the substrate and the K_i for various inhibitors agree well with values obtained by others using conventional methods.