Cloning and expression of hepatitis C virus serine protease gene
Objective To amplify and clone the HCV cDNA fragment that encode serine protease from the serum of a Chinese patient infected with HCV and express it in E.coli. Methods The HCV RNA was extracted from serum, the cDNA that encode HCV serine protease was amplified by RT PCR. Its sequence was determined by dideoxy chain termination method. It was subcloned into vector pBV220 and expressed in E.coli. The expressed recombinant protein was analysed by SDS PAGE electrophoresis and Western blot. Results The HCV serine cDNA was cloned. Sequence analysis showed that its reading frame is correct and no insert or deletion mutation happened. Homology comparison suggested it is from a HCV typeⅡ/1b isolate. This cDNA fragment was efficiently expressed in E.coli. Conclusion The serine protease cDNA was amplified successfully from the serum of a Chinese patient with HCV(Ⅱ/1b) infection. The expression of the serine protease in E.coli rollouted a basis for the study of its activity.