THE INFLUENCE OF pH ON THE HYDROLYSIS OF BENZOYLCHOLINE BY PSEUDOCHOLINESTERASE OF HUMAN PLASMA

Abstract

The study was performed with an automatic titrator and purified human pseudocholinesterase prepared from pooled plasma. The data obtained are compatible with the assumption that each enzyme molecule contains two binding sites for benzoylcholine which are unlike in their dependence on pH. Michaelis constants and maximum hydrolysis velocities were derived for each of the two binding sites, and acid–base dissociation constants of the enzyme substrate complexes were estimated.