title: Peptide-based inhibitors of the hepatitis C virus NS3 protease: structure-activity relationship at the C-terminal position.
abstract: The structure-activity relationship at the C-terminal position of peptide-based inhibitors of the hepatitis C virus NS3 protease is presented. The observation that the N-terminal cleavage product (DDIVPC-OH) of a substrate derived from the NS5A/5B cleavage site was a competitive inhibitor of the NS3 protease was previously described. The chemically unstable cysteine residue found at the P1 position of these peptide-based inhibitors could be replaced with a norvaline residue, at the expense of a substantial drop in the enzymatic activity. The fact that an aminocyclopropane carboxylic acid (ACCA) residue at the P1 position of a tetrapeptide such as 1 led to a significant gain in the inhibitory enzymatic activity, as compared to the corresponding norvaline derivative 2, prompted a systematic study of substituent effects on the three-membered ring. We report herein that the incorporation of a vinyl group with the proper configuration onto this small cycle produced inhibitors of the protease with much improved in vitro potency. The vinyl-ACCA is the first reported carboxylic acid containing a P1 residue that produced NS3 protease inhibitors that are significantly more active than inhibitors containing a cysteine at the same position.
authors.affiliation: Research and Development, Boehringer Ingelheim (Canada) Ltd, 2100 Cunard Street, Laval (Québec), Canada H7S 2G5. jrancourt@lav.boehringer-ingelheim.com
authors.forename: Jean
authors.initials: J
authors.lastname: Rancourt
authors.forename: Dale R
authors.initials: DR
authors.lastname: Cameron
authors.forename: Vida
authors.initials: V
authors.lastname: Gorys
authors.forename: Daniel
authors.initials: D
authors.lastname: Lamarre
authors.forename: Martin
authors.initials: M
authors.lastname: Poirier
authors.forename: Diane
authors.initials: D
authors.lastname: Thibeault
authors.forename: Montse
authors.initials: M
authors.lastname: Llinàs-Brunet
mesh_terms: D000598:Amino Acids, Cyclic / Q000138:chemical synthesis / Q000737:chemistry; D003521:Cyclopropanes / Q000138:chemical synthesis / Q000737:chemistry; D004791:Enzyme Inhibitors / Q000138:chemical synthesis / Q000737:chemistry*; D016174:Hepacivirus / Q000737:chemistry*; D008958:Models, Molecular; D008968:Molecular Conformation; D009842:Oligopeptides / Q000138:chemical synthesis / Q000737:chemistry*; D013237:Stereoisomerism; D013329:Structure-Activity Relationship; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D000598:Amino Acids, Cyclic; D003521:Cyclopropanes; D004791:Enzyme Inhibitors; D009842:Oligopeptides; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C023863:1-aminocyclopropane-1-carboxylic acid