Catalytic properties of peptides with hydrolytic activity.

The functional groups of the amino acids are the tools of catalysis in those enzymes which operate without coenzymes and cofactors [ 1,2]. Among the functional groups of proteins the imidazole, thiol and carboxyl groups are the most interesting ones with respect to their possible role in enzyme catalysis. While the mechanism of action of these groups in monofunctional catalysis has been thoroughly investigated [3], there exist only few studies on multifunctional cooperative catalysis including imidazole, thiol and carboxyl groups [4-71. We therefore have synthesized a number of peptides containing histidine, cystein and aspartic acid and have looked for possible cooperative effects of the functional groups by an extensive kinetic analysis of their catalytic properties in ester hydrolysis. In the present communication we report the first results of our studies on the catalytic properties of the synthetic peptides.