Stepwise degradation of the hexapeptide Met-Ala-Ser-Pro-Phe-Ala by dipeptidyl peptidase IV.
Dipeptidyl peptidase IV (dipeptidyl-peptide hydrolase, EC 3.4.14.-) purified from pig kidney was proved to split off the N-terminal dipeptide Met1-Ala2 and, subsequently the dipeptide Ser3-Pro4 from the synthetic model peptide Met-Ala-Ser-Pro-Phe-Ala representing the N-terminal part of a signal sequence of leucocyte interferon. The kinetic parameters for the release of Met1-Ala2 (Km 3.2.10(-5) mol.l-1 and Ser3-Pro4 (Km 1.65.10(-4) mol.l-1, kcat57.9 s-1) were determined. The dipeptides Ser-Pro and Phe-Ala were found to be competitive inhibitors of the hydrolysis of Gly-Pro-NHNp by dipeptidyl peptidase IV.
D000818:Animals; D018819:Dipeptidyl Peptidase 4; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D066298:In Vitro Techniques; D007370:Interferon Type I; D007668:Kidney / Q000201:enzymology; D007700:Kinetics; D009842:Oligopeptides; D010446:Peptide Fragments; D021382:Protein Sorting Signals; D013379:Substrate Specificity; D013552:Swine
D007370:Interferon Type I; D009842:Oligopeptides; D010446:Peptide Fragments; D021382:Protein Sorting Signals; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D018819:Dipeptidyl Peptidase 4