ON THE KINETICS OF THE HUMAN BLOOD CHOLINESTERASE

IV. THE INHIBITION OF CHOLINESTERASE BY SODIUM SALICYLATE

抄録

1. Sodium salicylate inhibits the cholinesterase in two different ways as the incubated concentration of the former differs.
2. It was indicated that the reversible inhibition, which is observed in the lower concentration range of salicylate, is non competitive. The inhibition seems to be brought about by combination of two molecules of salicylate to one enzyme molecule. The binding of one molecule of substrate to one enzyme molecule may result a hindrance of the binding of salicylate molecule with the latter.
3. In the irreversible inhibition by sodium salicylate which occurs in the higher concentration of the latter, the inactivation reaction of enzyme proceeds according to the first order kinetics, and is independent of substrate concentrations. The Arrhenius energy of this reaction was calculated to be 42, 000 cal.
The present investigation was supported by Prof. K. Kaziro, to whom the author's deep gratitude is due.