Étude de l'inhibition de l'activité estérasique de la trypsine par les dérivés acides et amides des esters spécifiques

Abstract

Abstract The inhibition of the esterase activity of trypsin (EC 3.4.4.4) by acid and amide derivatives of specific ester substrates has been determined at several pH values between 5 and 9 and at 25°. With either specific or non-specific ester substrates, the inhibition by the acid derivatives is stronger at low pH. The reverse is the case for the amide derivatives. The sigmoid curve of p K i dependency versus pH for both series of inhibitors suggests a very close interaction between the —COX group of the acid or amide derivatives and the histidine at the active center of the enzyme during the formation of the first non-covalent complex. The affinities of these different specific derivatives for the enzyme have been compared at the optimal pH value of the enzymatic activity.