Purification of ZntR (A) Fractionation by ammonium sulphate precipitation. Lanes 1, 2, 3, 4, 5, 6, and 7: Fractions obtained at 20%, 30%, 40%, 50%, 60%, 70%, and 80% saturation levels of ammonium sulphate, respectively. (B) Fractionation by anion exchange chromatography. Lane 1: Sample before FPLC; Lanes 2-8: Fractions obtained from anion exchange column HiTrap QFF. (C) Chromatogram showing elution profile of recombinant ZntR [X-axis, volume of buffer (mL), Y-axis OD280nm mAbs unit]. The peak represents maximum protein elution between 30-40% NaCl gradient. (D) SDS-PAGE showing protein after dialysis. Lane 1: Partially purified ZntR protein. Lane L: Protein ladder (Benchmark cat.no. 10747-012).