The effect of high pressure on peptide formation by the catalysis of carboxypeptidaseY (substitution of ester or peptide by amino acid derivative) or by thermolysin (condensation of N-acylamino acid and amino acid amide) was studied. The carboxypeptidase Y-catalyzed substitution reaction of N-[3-(2-furyl)acryloyl]phenylalanine ethyl ester with glycinamide or phenylalaninamide showed a six-fold higher
activity on these substrates. On the contrary, carboxypeptidase Y gave Fua-amino acids and Fua-dipeptides as products, depending on the structure of the substrates. Accordingly, liberations of free amino acids were detected in some cases. This result shows that the yeast enzyme acts on some of the substrates in a two step manner: First by amidase and second by a carboxypeptidase activity. Based on