Fig. 2.

Expression and purification of NS2B protein from bacteria. a. Schematic representation of an expression construct with NS2B in frame with the N-terminal V5 epitope and a 6° His tag. b Expression and purification of NS2B protein in bacteria. Cells were induced with 1 mM IPTG at zero time and analyzed by SDS-PAGE at the indicated times post-induction. c Expression and identification of recombinant NS2B protein at the indicated times post-IPTG induction by western blot analysis. The NS2B protein was detected using an anti-V5 antibody at a 1:5000 dilution. d Analysis of recombinant NS2B protein purification following different isolation steps by SDS-PAGE and Coomassie blue. Preparative gel electrophoresis and affinity chromatography were used for purification. Lane 1: inclusion bodies purified from bacteria expressing the NS2B protein. Lane 2: fraction obtained from preparative gels, in the molecular-weight region for of a 17-kDa protein. Lane 3: proteins not bound to the resin. Lane 4: fraction washes from the resin. Lanes 5–6: fraction containing the eluted and purified NS2B protein