Figure 4

Expression (A) and purification (B) of recombinant NnPAL1. A: The total proteins from E. coli BL21 are harvested at 4 h, 8 h and 12 h after post-induction, and 1 and 2 represent the total proteins of E .coli BL21 harbouring the pET28a(+) vector and recombinant pET28a(+)-NnPAL1 vector, respectively. B: A series of imidazole buffer concentration gradients (10 mM, 50 mM, 100 mM, 200 mM); lane1: the supernatant of the E. coli BL21 lysate harbouring the pET28a(+) vector; lane2: (native control) the supernatant of the E. coli BL21 lysate harbouring the pET28a(+)-NnPAL1 vector; lane3: the supernatant of the flow through of the Ni-IDA column for three replicates; lane 4, lane 5, lane 6, lane 7 and lane 8: the products washed with 10 mM, 20 mM, 50 mM, 100 mM, and 200 mM imidazole buffer, respectively.