FIG. 1.

Purification of the full-length NS3 protein from E. coli. (A) SDS-PAGE analysis of the purification steps. Lanes: 1, total extract; 2, soluble fraction; 3, inclusion bodies; 4, DEAE-Sepharose flowthrough; 5, 50% ammonium sulfate cut; 6, High Trap heparin-Sepharose; 7, poly(U)-Sepharose. M.W., molecular mass markers in kilodaltons. (B) Gel filtration analysis. A UV elution profile of a Superdex 200 analytical column is shown. Fractions of 0.6 ml were collected. The peaks in the chromatogram correspond to the monomeric and aggregated NS3 protein identified by Western blotting. The positions of the peaks corresponding to the molecular mass standard proteins are indicated by arrows. A₂₈₀, absorbance at 280 nm.