title: Hepatitis C virus NS3 protease requires its NS4A cofactor peptide for optimal binding of a boronic acid inhibitor as shown by NMR.
abstract: NMR spectroscopy was used to characterize the hepatitis C virus (HCV) NS3 protease in a complex with the 24 residue peptide cofactor from NS4A and a boronic acid inhibitor, Ac-Asp-Glu-Val-Val-Pro-boroAlg-OH. Secondary-structure information, NOE constraints between protease and cofactor, and hydrogen-deuterium exchange rates revealed that the cofactor was an integral strand in the N-terminal beta-sheet of the complex as observed in X-ray crystal structures. Based upon chemical-shift perturbations, inhibitor-protein NOEs, and the protonation state of the catalytic histidine, the boronic acid inhibitor was bound in the substrate binding site as a transition state mimic. In the absence of cofactor, the inhibitor had a lower affinity for the protease. Although the inhibitor binds in the same location, differences were observed at the catalytic site of the protease.
authors.affiliation: DuPont Pharmaceuticals Company, Wilmington, DE 19880, USA.
authors.forename: Sharon J
authors.initials: SJ
authors.lastname: Archer
authors.forename: Daniel M
authors.initials: DM
authors.lastname: Camac
authors.forename: Zhongren J
authors.initials: ZJ
authors.lastname: Wu
authors.forename: Neil A
authors.initials: NA
authors.lastname: Farrow
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Domaille
authors.forename: Zelda R
authors.initials: ZR
authors.lastname: Wasserman
authors.forename: Marina
authors.initials: M
authors.lastname: Bukhtiyarova
authors.forename: Christopher
authors.initials: C
authors.lastname: Rizzo
authors.forename: Sharada
authors.initials: S
authors.lastname: Jagannathan
authors.forename: Lawrence J
authors.initials: LJ
authors.lastname: Mersinger
authors.forename: Charles A
authors.initials: CA
authors.lastname: Kettner
mesh_terms: D001665:Binding Sites; D001897:Boronic Acids / Q000737:chemistry* / Q000494:pharmacology; D002352:Carrier Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D016174:Hepacivirus / Q000201:enzymology*; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D009682:Magnetic Resonance Spectroscopy; D011480:Protease Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000378:metabolism*; D014764:Viral Proteins / Q000737:chemistry*; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D001897:Boronic Acids; D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011480:Protease Inhibitors; D017361:Viral Nonstructural Proteins; D014764:Viral Proteins; C084422:NS3 protein, hepatitis C virus; D012697:Serine Endopeptidases; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C455041:NS4A cofactor peptide, Hepatitis C virus