Inhibition of histo-blood group antigen binding as a novel strategy to block norovirus infections

PLoS One. 2013 Jul 19;8(7):e69379. doi: 10.1371/journal.pone.0069379. Print 2013.

Abstract

Noroviruses (NoVs) are the most important viral pathogens that cause epidemic acute gastroenteritis. NoVs recognize human histo-blood group antigens (HBGAs) as receptors or attachment factors. The elucidation of crystal structures of the HBGA-binding interfaces of a number of human NoVs representing different HBGA binding patterns opens a new strategy for the development of antiviral compounds against NoVs through rational drug design and computer-aided virtual screening methods. In this study, docking simulations and virtual screening were used to identify hit compounds targeting the A and B antigens binding sites on the surface of the capsid P protein of a GII.4 NoV (VA387). Following validation by re-docking of the A and B ligands, these structural models and AutoDock suite of programs were used to screen a large drug-like compound library (derived from ZINC library) for inhibitors blocking GII.4 binding to HBGAs. After screening >2 million compounds using multistage protocol, 160 hit compounds with best predicted binding affinities and representing a number of distinct chemical classes have been selected for subsequent experimental validation. Twenty of the 160 compounds were found to be able to block the VA387 P dimers binding to the A and/or B HBGAs at an IC50<40.0 µM, with top 5 compounds blocking the HBGA binding at an IC50<10.0 µM in both oligosaccharide- and saliva-based blocking assays. Interestingly, 4 of the top-5 compounds shared the basic structure of cyclopenta [a] dimethyl phenanthren, indicating a promising structural template for further improvement by rational design.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antiviral Agents / chemistry
  • Antiviral Agents / pharmacology
  • Antiviral Agents / toxicity
  • Binding Sites
  • Blood Group Antigens / chemistry
  • Blood Group Antigens / metabolism*
  • Caliciviridae Infections / drug therapy
  • Caliciviridae Infections / metabolism*
  • Capsid Proteins / chemistry
  • Capsid Proteins / metabolism
  • Computer Simulation
  • Gastroenteritis / drug therapy
  • Gastroenteritis / metabolism*
  • High-Throughput Screening Assays
  • Humans
  • Molecular Docking Simulation
  • Norovirus / metabolism*
  • Oligosaccharides / chemistry
  • Oligosaccharides / metabolism
  • Protein Binding / drug effects
  • Protein Conformation
  • Protein Multimerization
  • Reproducibility of Results
  • Small Molecule Libraries

Substances

  • Antiviral Agents
  • Blood Group Antigens
  • Capsid Proteins
  • Oligosaccharides
  • Small Molecule Libraries