Kinetics of Hydrolysis of a New Peptide Substrate Containing p-Guanidino-L-phenylalanine by Trypsin and Thrombin

• Published in: Chemical & pharmaceutical bulletin Vol. 34; no. 3; pp. 1351 - 1354
• Main Authors: TSUNEMATSU, HIDEAKI, MIZUSAKI, KOICHI, HATANAKA, YOSHIHIRO, KAMAHORI, MASAO, MAKISUMI, SATORU
• Format: Journal Article
• Language: English
• Published: Tokyo The Pharmaceutical Society of Japan 1986; Maruzen
• Subjects: Analytical, structural and metabolic biochemistry; Animals; Applied sciences; Biological and medical sciences; Cattle; Enzymes and enzyme inhibitors; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Hydrolases; Hydrolysis; hydrolysis kinetics; Kinetics; Other techniques and industries; p-guanidino-L-phenylalanine; Peptides - metabolism; Phenylalanine - analogs & derivatives; Phenylalanine - metabolism; Substrate Specificity; thrombin; Thrombin - metabolism; trypsin; Trypsin - metabolism; Hydrolysis; Trypsin; Synthetic substrate; Peptides; Enzyme; Thrombin; Kinetics
• ISSN: 0009-2363; 1347-5223
• DOI: 10.1248/cpb.34.1351

A new peptide substrate containing p-guanidine-L-phenylalanine, Nα-benzoyl-L-phenylalanyl-L-prolyl-p-guanidino-L-phenylalanine p-nitroanilide (Bz-Phe-Pro-GPA-pNA), was synthesized, and the rates of hydrolyses of this substrate by bovine trypsin and thrombin were compared with those of the corresponding arginine peptide substrate (Bz-Phe-Pro-GPA-pNA). The specificity constants (kcat/Km) for the hydrolysis of GPA-peptide by the two enzymes were much smaller than those for Arg-peptide. Remarkably low kcat values were found in the hydrolyses of GPA-peptide by the two enzymes compared with the values in those of Arg-peptide. The effect of the peptide chain elongation was observed in the hydrolysis of GPA-peptide by thrombin, while it was not in the case of trypsin, suggesting that the subsite of trypsin is very different from that of thrombin. GPA-peptide was ascertained to be a useful peptide substrate to study the subsite specificities of trypsin-like enzymes.