[Theoretical conformational analysis of a substrate component of tetrahedral intermediates and of acyl-enzyme of carboxypeptidase A].

Semi-empirical calculation of conformational properties of covalent complexes of carboxypeptidase A with ester and peptide substrates are presented. There is a favourable form of transient tetrahedral and covalent acyl-enzyme intermediates in the active site of carboxypeptidase A. The ester and peptide substrates bind in the active site of carbopeptidase A in the same mode. The transition from one stage of the reaction to the other is followed by a small conformational change. The atom coordinates of the substrate component of these complexes are presented.