Hepatitis C virus NS3 protease requires its NS4A cofactor peptide for optimal binding of a boronic acid inhibitor as shown by NMR.
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.
Archer
Sharon J
SJ
DuPont Pharmaceuticals Company, Wilmington, DE 19880, USA.
Camac
Daniel M
DM
Wu
Zhongren J
ZJ
Farrow
Neil A
NA
Domaille
Peter J
PJ
Wasserman
Zelda R
ZR
Bukhtiyarova
Marina
M
Rizzo
Christopher
C
Jagannathan
Sharada
S
Mersinger
Lawrence J
LJ
Kettner
Charles A
CA
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
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