Identification of a new region of SARS-CoV S protein critical for viral entry

J Mol Biol. 2009 Dec 11;394(4):600-5. doi: 10.1016/j.jmb.2009.10.032. Epub 2009 Oct 21.


Infection by severe acute respiratory syndrome coronavirus (SARS-CoV) is initiated by specific interactions between the SARS-CoV spike (S) protein and its receptor ACE2. In this report, we screened a peptide library representing the SARS-CoV S protein sequence using a human immunodeficiency virus-based pseudotyping system to identify specific regions that affect viral entry. One of the 169 peptides screened, peptide 9626 (S residues 217-234), inhibited SARS-CoV S-mediated entry of the pseudotyped virions in 293T cells expressing a functional SARS-CoV receptor (human angiotensin-converting enzyme 2) in a dose-dependent manner (IC(50) approximately 11 microM). Alanine scanning mutagenesis was performed to assess the roles of individual residues within this region of S, which was previously uncharacterized. The effects included significant reductions in expression (K223A), viral incorporation (L218A, I230A, and N232A), and reduced viral entry (L224A, L226A, I228A, T231A, and F233A). Taken together, these results reveal a new region of the S protein that is crucial for SARS-CoV entry.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Substitution / genetics
  • Angiotensin-Converting Enzyme 2
  • Antiviral Agents / pharmacology
  • Cell Line
  • HIV / genetics
  • Host-Pathogen Interactions / drug effects
  • Humans
  • Inhibitory Concentration 50
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Mutagenesis, Site-Directed
  • Peptides / pharmacology
  • Peptidyl-Dipeptidase A / metabolism*
  • Receptors, Virus / metabolism
  • Severe acute respiratory syndrome-related coronavirus / physiology*
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins / genetics
  • Viral Envelope Proteins / metabolism*
  • Virus Internalization*


  • Antiviral Agents
  • Membrane Glycoproteins
  • Peptides
  • Receptors, Virus
  • Spike Glycoprotein, Coronavirus
  • Viral Envelope Proteins
  • spike glycoprotein, SARS-CoV
  • spike protein, mouse hepatitis virus
  • Peptidyl-Dipeptidase A
  • ACE2 protein, human
  • Angiotensin-Converting Enzyme 2