Enhancement of humoral immune responses to HBsAg by heat shock protein gp96 and its N-terminal fragment in mice

Figure 2 Expression and purification of the N-terminal fragment of gp96 in the GST fusion expression system. A: The resulting protein N-terminal fragment of gp96 (named after NTF) was separated from the digestion product on a glutathione±Sepharose 4B column to remove GST and GST-3C protease. Lane 1, 10% SDS±PAGE of GST-NTF eluted by reduced glutathione; lane 2, NTF after GST-3C protease digestion (16 h, 5 °C); lane 3, NTF after removing GST and GST-3C protease; lane 4, purified GST as control; M, protein molecular weight markers as indicated in kilo Daltons; B: Gel-filtration analysis of NTF protein. NTF protein subjected to Superdex G75 gel-filtration; C: The proteins from the peak run on 10% SDS-PAGE and Western blot. The standard proteins are superimposed in both A and C.