Action of Carboxypeptidase Toward Peptides Containing Unnatural Aromatic Amino Acids.

摘要

Since Beta-2-thienylalanine has been found to inhibit the growth of certain organisms through interference with the metabolism of its analogue, phenylalanine (2, 3), it seemed of interest to prepare peptides containing this and other unnatural aromatic amino acids, and to determine whether these peptide analogues would be antagonistic to the action of isolated proteolytic enzyme systems, as well as to the growth of microorganisms. Carboxypeptidase from beef pancreas was selected as the enzyme to use in this study because it displays maximum activity toward substrates derived from aromatic amino acids, and because it can be isolated readily in pure form. Carbobenzoxyglycylphenylalanine (I) is hydrolyzed by carboxypeptidase more readily than any other synthetic peptide, and its racemate has been suggested as a standard for measurement of carhoxypeptidase activity (5). Therefore, the compounds herein reported were fashioned after this peptide, and differ from it only by replacement of the benzene ring with other aromatic rings.