Obtaining of purified hepatitis C virus envelope glycoprotein

Hepatitis C Virus (HCV) infection is a major public health issue. HCV has a propensity to develop chronic infections which may proceed to cirrhosis and hepatocellular carcinoma. One of the hallmarks of the chronic infection is the quasispecies nature of the viral population which favors the selection of variants that may escape the host immune responses. Envelope glycoproteins (E1 and E2) are constantly under selective pressures resulting in the selection of viral variants that can escape antibody responses. E1 protein also plays important roles in viral attachment and entry into target cells as well as in the modulation of host immune responses. In this study, we report the cloning and prokaryotic expression of a genotype 1b HCV E1 molecule.For the expression of HCV E1 protein in E. coli, full-length and C-terminally truncated E1 sequences from a clinical isolate of subtype 1b virus were amplified by PCR. Resulting fragments were cloned into pQE30 vector and subsequently expressed in E. coli as His-tagged proteins. The E1 proteins were characterized by SDS-PAGE. The immunologic reactivity of the proteins were evaluated by western blot (WB) analysis using anti-HCV positive serum samples.Full-length and C- terminally truncated E1 were successfully expressed in prokaryotic system as hexa-histidine-tagged recombinant fusion proteins. The proteins self-assembled into dimers and trimers as shown by PAGE and WB PAGE analyses. Recombinant E1 proteins were also immunologically reactive using polyclonal sera from HCV infected patients.Prokaryotic expression of full-length viral membrane proteins can be difficult. We report here the successful expression of the immunologically reactive full-length and truncated E1 proteins for the first time in Turkey. The rE1 proteins can be important tools fur further diagnostic and immunological studies.Key words : HCV envelope protein 1; Recombinant proteins; Escherichia coli