Bacterial expression and analysis of cleavage activity of HCV serine proteinase using recombinant and synthetic substrate.

HCV encoding serine proteinase was expressed in E. coli as a fused form with maltose binding protein (MBP) and a six histidine tag. The enzyme was partially purified by using affinity chromatography for these fused peptides. Proteolytic cleavage activity of the partially purified enzyme was detected by means of an assay using both a recombinant protein and a synthetic peptide substrate which had an amino acid sequence corresponding to the most efficient cleavage site in vivo, the NS5A-NS5B junction. The cleavage occurred at the same site that was reported before.