Figure 1.

SDS-PAGE analysis of the expression of FLA protein in Escherchia coli. The total proteins of the E. coli BL21 harboring pET28a/fliC vector was harvested and loaded on 12% (v/v) SDS-PAGE after 4 hr induction with or without Isopropyl-β-D-thiogalactoside (IPTG). Lane M denotes marker proteins with the indicated molecular weight; (Lanes 1 and 2): purified FLA after HisTrap chelating and Ni2+-affinity chromatography (~ 45 kDa); (Lane 3): total cell lysate of non-induced bacteria; (lanes 4-7) 1-4 hr after the induction