FIG. 3.

Expression and purification of rMTB12 proteins. Recombinant proteins corresponding to full-length MTB12 protein (A) or mature MTB12 protein lacking the leader sequence (B), both containing amino-terminal six-histidine tags, were expressed by using the pET17b E. coli high-level expression system. Lysates of uninduced cultures (lane 1), IPTG-induced cultures (lane 2), and affinity-purified recombinant protein (lane 3) were fractionated by SDS-PAGE and stained with Coomassie blue. Positions of size markers (lane M) are indicated in kilodaltons.