Crystal structure of HCV NS3/4A protease in complex with voxilaprevir

Experimental Data Snapshot

  • Resolution: 1.40 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.176 
  • R-Value Observed: 0.177 

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This is version 1.2 of the entry. See complete history


Discovery of the pan-genotypic hepatitis C virus NS3/4A protease inhibitor voxilaprevir (GS-9857): A component of Vosevi®.

Taylor, J.G.Zipfel, S.Ramey, K.Vivian, R.Schrier, A.Karki, K.K.Katana, A.Kato, D.Kobayashi, T.Martinez, R.Sangi, M.Siegel, D.Tran, C.V.Yang, Z.Y.Zablocki, J.Yang, C.Y.Wang, Y.Wang, K.Chan, K.Barauskas, O.Cheng, G.Jin, D.Schultz, B.E.Appleby, T.Villasenor, A.G.Link, J.O.

(2019) Bioorg Med Chem Lett 29: 2428-2436

  • DOI: https://doi.org/10.1016/j.bmcl.2019.03.037
  • Primary Citation of Related Structures:  
    6NZT, 6NZV

  • PubMed Abstract: 

    Treatment of hepatitis C virus (HCV) infection has been historically challenging due the high viral genetic complexity wherein there are eight distinct genotypes and at least 86 viral subtypes. While HCV NS3/4A protease inhibitors are an established treatment option for genotype 1 infection, limited coverage of genotypes 2 and/or 3 combined with serum alanine transaminase (ALT) elevations for some compounds has limited the broad utility of this therapeutic class. Our discovery efforts were focused on identifying an NS3/4A protease inhibitor with pan-genotypic antiviral activity, improved coverage of resistance associated substitutions, and a decreased risk of hepatotoxicity. Towards this goal, distinct interactions with the conserved catalytic triad of the NS3/4A protease were identified that improved genotype 3 antiviral activity. We further discovered that protein adduct formation strongly correlated with clinical ALT elevation for this therapeutic class. Improving metabolic stability and decreasing protein adduct formation through structural modifications ultimately resulted in voxilaprevir. Voxilaprevir, in combination with sofosbuvir and velpatasvir, has demonstrated pan-genotypic antiviral clinical activity. Furthermore, hepatotoxicity was not observed in Phase 3 clinical trials with voxilaprevir, consistent with our design strategy. Vosevi ® (sofosbuvir, velpatasvir, and voxilaprevir) is now an approved pan-genotypic treatment option for the most difficult-to-cure individuals who have previously failed direct acting antiviral therapy.

  • Organizational Affiliation

    Medicinal Chemistry, Gilead Sciences, 333 Lakeside Drive, Foster City, CA 94404, United States. Electronic address: james.taylor@gilead.com.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
HCV NS3/4A protease203Hepacivirus hominisMutation(s): 11 
Find proteins for S4UY05 (hepatitis C virus genotype 1a)
Explore S4UY05 
Go to UniProtKB:  S4UY05
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupS4UY05
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.40 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.176 
  • R-Value Observed: 0.177 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 55.194α = 90
b = 59.009β = 90
c = 60.166γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-07-10
    Type: Initial release
  • Version 1.1: 2019-08-21
    Changes: Data collection, Database references
  • Version 1.2: 2023-10-11
    Changes: Data collection, Database references, Refinement description