A new class of potent reversible inhibitors of metallo-proteinases: C-terminal thiol-peptides as zinc-coordinating ligands.
A number of substrate analogous peptides containing a phosphoramidate, phosphonate ester, hydroxamate, carboxylate or sulfhydryl group are known to be inhibitors of thermolysin and other metalloproteinases. According to the specificity, most of the inhibitors mimic the prime site of the active center. Hitherto, peptidyl derivatives with a thiol group at the C-terminus have not been described. We have synthesized the protected cysteamides Ac-Ala-Ala-CA-SH and Z-Aa1-Aa2-CA-SH (Aa1: Ala, Pro; Aa2: Ala, Leu). The binding of these thiol peptide inhibitors to the metalloproteinases is characterized first by the coordination of the thiolate group of the inhibitor to the catalytic zinc ion and second by the subsite interaction of the peptide ligand in the active site of the enzyme. All peptide derivatives were competitive inhibitors of the zinc metalloproteinase thermolysin. The strongest inhibition was found with Z-Pro-Leu-CA-SH (Ki = 30 microM). Substitution of the N-protecting benzyloxycarbonyl residue towards the acetyl group in the peptide inhibitor, the inhibition constant decreased about 25 times.
Peters
K
K
Faculty of Medicine, Institute of Physiological Chemistry, Martin Luther University, Halle-Wittenberg, Halle (Saale), Germany. peters@chemie.uni-halle.de
Jahreis
G
G
Kotters
E M
EM
D001665:Binding Sites; D004791:Enzyme Inhibitors / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D007700:Kinetics; D008024:Ligands; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors*; D008958:Models, Molecular; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013329:Structure-Activity Relationship; D013438:Sulfhydryl Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D013820:Thermolysin / Q000037:antagonists & inhibitors; D015032:Zinc / Q000737:chemistry
D004791:Enzyme Inhibitors; D008024:Ligands; D009842:Oligopeptides; D013438:Sulfhydryl Compounds; D008666:Metalloendopeptidases; D013820:Thermolysin; D015032:Zinc