HIGN LEVEL EXPRESSION OF HEPATITIS C VIRUS CORE GENE IN E.COLI

Hepatitis C virus (HCV) is the major agentfor the posttransfusinal and diffusive non- A,non-B hepatitis that could transform to chronic hepati-tis,and also has close relation to liver cancer andcirrhosis1] .HCV is a single positive- stranded RNA viruswhose genome(about9.4kilobases) contains asingle uninterrupted open reading frame (ORF )which encodes a polyprotein precursor of 30 1 0～30 1 1 amino acid residues.The genome of HCV issimilar to flavivirus and pestivirus.In vitrostudieshav…

HIGN LEVEL EXPRESSION OF HEPATITIS C VIRUS CORE GENE IN E. COLI

Objective To express the hepatitis C virus (HCV) core gene in E . coli on a high level. Methods　 The cDNA coding for HCV core protein was amplified by polymerase chain reaction (PCR). The PCR product was　 purified and digested with restriction enzymes and inserted into the downstream of PRPL promoter of a high-level ex- pression vector pBV220. HCV core gene was expressed in E. coli in a non-fused form. The expression protein was analysed by SDS-PAGE , and its immunoactivity was tested by ELISA. Results Sequence analysis of the amplified PCR products confirmed that we have successfully cloned and expresssed the intact core protein of HCV. SDS-PAGE showed that a specific protein with a molecular weight of 21kDa at a level of 14. 0％ of the total bacterial proteins ap- peared in bacteria harboring pBV/HCVCore, while this protein was absent in the control bacteria harboring pBV220. The results of enzyme immunoassay analysis showed that this protein could be specifically recognized by the HCV pos- itive sera from patients with hepatitis C . Conclusion The intact HCV core protein was successfully expressed in E . coli in a non-fused form on a high level, and its immunoactivity was high.