Inhibitors of Tripeptidyl Peptidase II. 2. Generation of the First Novel Lead Inhibitor of Cholecystokinin-8-Inactivating Peptidase:  A Strategy for the Design of Peptidase Inhibitors

• Published in: Journal of medicinal chemistry 2000-02, Vol.43 (4), p.664-674
• Main Authors: Ganellin, C. Robin, Bishop, Paul B, Bambal, Ramesh B, Chan, Suzanne M. T, Law, James K, Marabout, Benoit, Luthra, Pratibha Mehta, Moore, Andrew N. J, Peschard, Olivier, Bourgeat, Pierre, Rose, Christiane, Vargas, Froylan, Schwartz, Jean-Charles
• Format: Article
• Language: English
• Subjects: Aminopeptidases; Analytical, structural and metabolic biochemistry; Animals; Biological and medical sciences; Cerebral Cortex - metabolism; Dipeptides - chemical synthesis; Dipeptides - chemistry; Dipeptides - pharmacology; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Drug Design; Enzymes and enzyme inhibitors; Fundamental and applied biological sciences. Psychology; Hydrolases; In Vitro Techniques; Medical sciences; Miscellaneous; Oligopeptides - chemical synthesis; Oligopeptides - chemistry; Oligopeptides - pharmacology; Pharmacology. Drug treatments; Rats; Serine Endopeptidases - metabolism; Serine Proteinase Inhibitors - chemical synthesis; Serine Proteinase Inhibitors - chemistry; Serine Proteinase Inhibitors - pharmacology; Sincalide - metabolism; Structure-Activity Relationship
• ISSN: 0022-2623; 1520-4804
• DOI: 10.1021/jm990226g

The cholecystokinin-8 (CCK-8)-inactivating peptidase is a serine peptidase which has been shown to be a membrane-bound isoform of tripeptidyl peptidase II (EC 3.4.14.10). It cleaves the neurotransmitter CCK-8 sulfate at the Met−Gly bond to give Asp-Tyr(SO3H)-Met-OH + Gly-Trp-Met-Asp-Phe-NH2. In seeking a reversible inhibitor of this peptidase, the enzymatic binding subsites were characterized using a fluorimetric assay based on the hydrolysis of the artificial substrate Ala-Ala-Phe-amidomethylcoumarin. A series of di- and tripeptides having various alkyl or aryl side chains was studied to determine the accessible volume for binding and to probe the potential for hydrophobic interactions. From this initial study the tripeptides Ile-Pro-Ile-OH (K i = 1 μM) and Ala-Pro-Ala-OH (K i = 3 μM) and dipeptide amide Val-Nvl-NHBu (K i = 3 μM) emerged as leads. Comparison of these structures led to the synthesis of Val-Pro-NHBu (K i = 0.57 μM) which served for later optimization in the design of butabindide, a potent reversible competitive and selective inhibitor of the CCK-8-inactivating peptidase. The strategy for this work is explicitly described since it illustrates a possible general approach for peptidase inhibitor design.