Publications & Reports

Large-scale production and characterization of recombinant human immunodeficiency virus type 1 Nef.

Azad AA, Failla P, Lucantoni A, Bentley J, Mardon C, Wolfe A, Fuller K, Hewish D, Sengupta S, Sankovich S, Grgacic E, Mcphee D, Macreadie I
Biomolecular Research Institute, Parkville, Victoria, Australia.

Abstract

Sequences encoding the 27K and 25K nef gene products (Nef 27 and Nef 25) were amplified by PCR from a human immunodeficiency virus type 1 infectious clone and subcloned directly into Escherichia coli, yeast and baculovirus expression vectors. The yeast- and baculovirus-derived Nef had native N termini but the expression levels were low. The expression levels of the E. coli-derived glutathione S-transferase-Nef fusion proteins were very high and a major portion was soluble. Large-scale production of E. coli-derived Nef 27 and Nef 25 was carried out by growing recombinant cells in a fermenter under fed-batch conditions followed by affinity purification on glutathione-Sepharose before and after thrombin cleavage. Large quantities of highly purified recombinant Nef proteins have been produced for functional and structural studies. Under non-reducing conditions both Nef 27 and Nef 25 existed as a mixture of monomers, dimers and small amounts of higher oligomers, but when reduced were monomeric. The highly purified Nef proteins had no G protein activities, however Nef 27 was biologically active. When electroporated into uninfected CD4+ T lymphocytes both E. coli-derived Nef 27 and yeast-derived myristylated Nef 27 down-regulated the surface expression of CD4, demonstrating that this method can be used to assess the biological activity of purified recombinant Nef.

Publication

  • Journal: The Journal of General Virology
  • Published: 01/03/1994
  • Volume: 75 ( Pt 3)
  • Pagination: 651-655