FIG. 3.

Expression and purification of soluble Gag proteins from Sf9 cells. (A) Intracellular expression levels of Gag with C-terminal truncations. Sf9 cells expressing each truncated Gag protein were lysed and directly subjected to SDS-PAGE followed by Western blotting using an antipolyhistidine monoclonal antibody (Sigma). (B) Purification yields of Gag with C-terminal truncations. Following disruption of Sf9 cells expressing each truncated Gag protein, soluble Gag proteins were purified from the clarified cell lysates by metal chelate chromatography and subjected to SDS-PAGE followed by staining with Coomassie brilliant blue. Lanes: M, prestained molecular weight markers (Bio-Rad); 1 to 6, MA, MA-CA, MA-CA-p2, MA-CA-p2-NCdl1, MA-CA-p2-NCdl2, and MA-CA-p2-NC, respectively.