P. Sundaram et Jl. Brandsma, RAPID, EFFICIENT, LARGE-SCALE PURIFICATION OF UNFUSED, NON-DENATURED E7 PROTEIN OF COTTONTAIL RABBIT PAPILLOMAVIRUS, Journal of virological methods, 57(1), 1996, pp. 61-70
Citations number
28
Categorie Soggetti
Virology,"Biochemical Research Methods","Biothechnology & Applied Migrobiology
Cottontail rabbit papillomavirus (CRPV) E7 protein is one of the 'high
risk' papillomavirus E7 oncoproteins that are partially insoluble in
aqueous solution. An Escherichia coli expression system was used for p
urification of CRPV E7 protein in quantities sufficient for immunologi
c studies and structural analysis. A glutathione S-transferase (GST)-C
RPV E7 fusion protein was solubilized in the presence of non-ionic and
ionic detergents, and isolated on an affinity column of glutathione S
epharose beads. The CRPV E7 portion was cleaved from the column with t
hrombin at a thrombin cleavage site between the fused partners. Thromb
in was removed subsequently by adsorption to benzamidine. This method
is rapid, requiring just one week, and efficient, yielding 3 mg of pur
e CRPV E7 protein per liter of bacterial culture. It produced a protei
n product that was about 95% pure. High-titered polyclonal antisera ge
nerated to the product recognized CRPV E7 but not GST. Purified CRPV E
7 protein exhibited the ability to bind pRB, making it the first unfus
ed, non-denatured CRPV E7 product reported to do so. This attribute co
uld facilitate structure-function studies of CRPV E7-pRB interactions.