Study on the expression of a substrate-based polypeptide and its inhibition against HCV protease in vitro / 中华微生物学和免疫学杂志

ABSTRACT

Objective To synthesize an inhibitory peptide against serine protease of hepatitis C virus(HCV)and explore its inhibition ability in vitro. Methods Based on the sequence characteristics of four natural substrates of protease in HCV,the gene sequence of an inhibitory peptide against HCV serine protease was designed and directly synthesized by PCR. The segment was subcloned into prokaryotic expression vector pBVIL1,resulting in the construction of the recombinant plasmid pBVIL1/IP,which was then transformed into E. coli HB101 strain. Purified by ion exchange chromatography,the expressed protein was added into an in vitro system,which was comprised of the inhibitory peptide(expressed protein),protease and the substrate,i.e. a NS5A-B fragment,in phosphate buffer. Then SDS-PAGE was performed to test the inhibition effect of the polypeptide. Results The recombinant expression vector pBVIL1/IP containing target gene was successfully constructed. The peptide expressed as inclusion boay was identified by SDS-PAGE. The degradation of protease substrate NS5A-B fragment is inhibited proportionally with the increasing concentrations of the peptide. Conclusion The recombinant peptide shows inhibitory effect on HCV protease in vitro.