Fusion core structure of the severe acute respiratory syndrome coronavirus (SARS-CoV): in search of potent SARS-CoV entry inhibitors

J Cell Biochem. 2008 Aug 15;104(6):2335-47. doi: 10.1002/jcb.21790.


Severe acute respiratory coronavirus (SARS-CoV) spike (S) glycoprotein fusion core consists of a six-helix bundle with the three C-terminal heptad repeat (HR2) helices packed against a central coiled-coil of the other three N-terminal heptad repeat (HR1) helices. Each of the three peripheral HR2 helices shows prominent contacts with the hydrophobic surface of the central HR1 coiled-coil. The concerted protein-protein interactions among the HR helices are responsible for the fusion event that leads to the release of the SARS-CoV nucleocapsid into the target host-cell. In this investigation, we applied recombinant protein and synthetic peptide-based biophysical assays to characterize the biological activities of the HR helices. In a parallel experiment, we employed a HIV-luc/SARS pseudotyped virus entry inhibition assay to screen for potent inhibitory activities on HR peptides derived from the SARS-CoV S protein HR regions and a series of other small-molecule drugs. Three HR peptides and five small-molecule drugs were identified as potential inhibitors. ADS-J1, which has been used to interfere with the fusogenesis of HIV-1 onto CD4+ cells, demonstrated the highest HIV-luc/SARS pseudotyped virus-entry inhibition activity among the other small-molecule drugs. Molecular modeling analysis suggested that ADS-J1 may bind to the deep pocket of the hydrophobic groove on the surface of the central coiled-coil of SARS-CoV S HR protein and prevent the entrance of the SARS-CoV into the host cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Antiviral Agents / pharmacology*
  • Computational Biology
  • HIV-1 / metabolism
  • Lasers
  • Luciferases / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Peptides / chemistry
  • Peptides / metabolism
  • Protein Binding
  • Protein Folding
  • Protein Structure, Secondary
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Repetitive Sequences, Nucleic Acid
  • Scattering, Radiation
  • Severe acute respiratory syndrome-related coronavirus / chemistry*
  • Thermodynamics
  • Viral Fusion Proteins / chemistry*
  • Virus Internalization / drug effects*


  • Antiviral Agents
  • Peptides
  • Recombinant Proteins
  • Viral Fusion Proteins
  • Luciferases