Folding and oligomerization of the gp2b/gp3/gp4 spike proteins of equine arteritis virus in vitro

Viruses. 2012 Mar;4(3):414-23. doi: 10.3390/v4030414. Epub 2012 Mar 22.


Equine arteritis virus (EAV) is a small, positive-stranded RNA virus. The glycoproteins gp2b, gp3 and gp4 form a heterotrimer in the viral envelope, which is required for cell entry of EAV. We describe expression of the ectodomains of the proteins in E. coli and their refolding from inclusion bodies. After extraction of inclusion bodies and dialysis, Gst-, but not His-tagged proteins, refold into a soluble conformation. However, when dialyzed together with Gst-gp3 or with Gst-gp4, His-gp2b and His-gp4 remain soluble and oligomers are obtained by affinity-chromatography. Thus, folding and oligomerization of gp2b, gp3 and gp4 in vitro are interdependent processes.

Keywords: equine arteritis virus; glycoproteins; gp2b; gp3; gp4; protein folding, oligomerization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatography, Affinity
  • Equartevirus / chemistry*
  • Escherichia coli
  • Protein Conformation
  • Protein Folding
  • Protein Multimerization
  • Protein Structure, Tertiary
  • Recombinant Proteins / chemistry
  • Viral Envelope Proteins / chemistry*


  • GP3 protein, equine arteritis virus
  • GP4 protein, equine arteritis virus
  • Recombinant Proteins
  • Viral Envelope Proteins