Figure 4.

Purified MBP-NaKR1 Fusion Protein Binds Heavy Metals.

MBP-NaKR1 or MBP (control) were expressed in E. coli BL21-AI and purified using amylose resin.

(A) Coomassie blue–stained polyacrylamide gel (12%) showing 3 μg purified MBP-NaKR1 (lane 2) and 3 μg MBP (lane 3). Lane 1 contained low-range SDS-PAGE standards (Bio-Rad).

(B) Metal content of the purified protein samples MBP-NaKR1 and MBP. Average metal concentration from two independent experiments is presented. The metal concentrations were determined by ICP-MS analysis.

(C) Molar ratio of heavy metal to protein in purified MBP-NaKR1 samples. The metal concentrations were determined by ICP-MS analysis and protein concentrations by amino acid analysis. The values represent the average of results from two independent experiments.