FIGURE 7.

Purification and PPO activity assay of the active His₆-tagged CatA, Hpi, and Hpii. (A) The proteins purified by Ni (II)-bound affinity chromatography were analyzed by SDS-PAGE (12%).Gel lanes: M, molecular weight marker; (1) the cell lysates from E. coli BL21(DE3) harboring pET-26b(+); (2) the cell lysates from E. coli BL21(DE3) harboring pET-CatA; (3) His₆-tagged CatA purified; (4) the cell lysates from E. coli BL21(DE3) harboring pET-Hpii; (5) His₆-tagged Hpii purified; (6) the cell lysates from E. coli BL21(DE3) harboring pET-Hpi; (7) His₆-tagged Hpi purified. (B) PPO (PPO) activity analysis of purified proteins was carried out on native-PAGE. Gel lanes: (1) purified CatA stained by coomassie brilliant blue; (2) purified Hpii stained by Coomassie brilliant blue; (3) purified Hpi stained by Coomassie brilliant blue; (4) purified CatA stained by L-DOPA; (5) purified Hpii stained by L-DOPA; (6) purified Hpi stained by L-DOPA.