FIG. 1.
Expression and purification of (His)6-tagged HCV NS5B from E. coli. (A) Imidazole elution profile of the NS5B expressed in E. coli. Fractions eluted from Ni-NTA resin by different concentrations of imidazole were run in an SDS–10% polyacrylamide gel and stained with Coomassie brilliant blue G-250. (B) Western blot analysis of NS5B. Fractions eluted with 200 mM imidazole were used for immunoblotting. Vector and NS5B indicate the fractions obtained from the soluble extracts of E. coli transformed with the expression vector alone and the NS5B-expression vector, pThNS5B, respectively. Arrowheads indicate the positions of NS5B. The sizes of protein markers (Bethesda Research Laboratories) are indicated in kilodaltons.