Fig. 4

SDS–PAGE analysis of His-fRv3391 purification. The recombinant protein was purified to homogeneity using the His-bind column protein purification kit (a) and Sephadex G-75 column chromatography (b). a Lane 1 fraction washed with 250 mM imidazole; lane 2 fraction washed with 100 mM imidazole; lane 3 fraction washed with 50 mM imidazole; lane 4 crude supernatant fraction before addition to the Ni-NTA column; lane 5 the non-induced BL21 cells; lane 6 molecular weight markers (P7708; New England Biolabs, USA). b Lane 1 molecular weight markers (P7708; New England Biolabs); lane 2 purified His-fRv3391 after Sephadex G-75 column chromatography. Proteins were visualized with Coomassi brilliant blue staining