Expression, purification and sublocalization of SARS-CoV nucleocapsid protein in insect cells

Acta Biochim Biophys Sin (Shanghai). 2004 Nov;36(11):754-8. doi: 10.1093/abbs/36.11.754.

Abstract

The causative agent of severe acute respiratory syndrome (SARS) is a previously unidentified coronavirus, SARS-CoV. The nucleocapsid (N) protein of SARS-CoV is a major viral protein recognized by acute and early convalescent sera from SARS patients. To facilitate the studies on the function and structure of the N protein, this report describe the expression and purification of recombinant SARS-CoV N protein using the baculovirus expression system. Recombinant hexa-histidine-tagged N protein with a molecular mass of 47 kD was produced in insect cells. Recombinant N protein was purified to near homogeneity by Ni2+-NTA affinity chromatography. In addition, we examined the subcellular localization of the N protein by confocal microscopy in Trichoplusia ni BT1 Tn 5B1-4 cells infected with recombinant baculovirus. The N protein was found localized in the cytoplasm as well as in the nucleolus. The purified recombinant N protein can be used in further functional study of SARS-CoV.

MeSH terms

  • Animals
  • Blotting, Western
  • Cell Line
  • Coronavirus Nucleocapsid Proteins
  • Cytoplasm / chemistry
  • Electrophoresis, Polyacrylamide Gel
  • Escherichia coli / metabolism
  • Humans
  • Insecta
  • Microscopy, Confocal
  • Microscopy, Fluorescence
  • Nucleocapsid Proteins / chemistry*
  • Nucleocapsid Proteins / isolation & purification*
  • Nucleocapsid Proteins / metabolism
  • Plasmids / metabolism
  • Protein Conformation
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Severe acute respiratory syndrome-related coronavirus / metabolism*

Substances

  • Coronavirus Nucleocapsid Proteins
  • Nucleocapsid Proteins
  • Recombinant Proteins