Overexpression and simple purification of a truncated, immunologically reactive GST-HCV core (1-123) fusion protein

A full-length and a truncated gene for the core protein of hepatitis C virus (HCV) were linked to the gene for glutathione S-transferase (GST), and the expression of each GST-HCV core fusion protein was analyzed. The truncated GST-HCV core (1-123) fusion protein was expressed as a mostly soluble and partly insoluble form comprising more than 50% of the total protein in Escherichia coli after induction by isopropylthio-beta-D-galactoside (IPTG), while the full length GST-HCV core (1-191) fusion protein was not expressed, suggesting that the hydrophobic carboxy terminal region in the core protein affects its expression. In addition, the GST-HCV core (1-123) fusion protein purified by GST-agarose chromatography reacted specifically with an anti-HCV serum from a patient.