Action on peptides by wheat carboxypeptidase

A kinetic analysis has been performed with purified wheat carboxypeptidase by the use of N-acyl dipeptides, Z-Gly-Pro-Leu-Gly (Z = benzyloxycarbonyl), angiotensin II and bradykinin. The values of k_cat were dramatically influenced by amino acid residues occupying the penultimate position from the carboxyl terminus of substrates. The structure of the substrate did not appreciably affect the K_m values.