Influence of potassium and calcium chlorides on the anticholine sterase activity of esters of diphenylphosphinic and diphenylthiophosphinic acids

Abstract

1. The influence of KCl and CaCl2 on the inhibition of the catalytic activity of butyrylcholinesterase (BuCE) and acetylcholinesterase (ACE) by cationic organophosphorus inhibitors with combined action and with a reversible type of inhibition was investigated at 25‡, pH 7.5, and ionic strength (Μ) 0.0044, 0.11, and 0.55. Increasing Μ reduces irreversible and reversible inhibition. 2. In the case of the same increase in Μ, the influence of KCl on the values of the inhibitor constants, as a rule, was substantially greater than the influence of CaCl2; ACE proved to be more sensitive to a change in Μ than BuCE. The presence of specific salt effects in the reactions of cholinesterases was demonstrated.