FIG. 3.

(a) Coomassie blue-stained SDS-PAGE of the fractions obtained during purification of His₆-BceD from E. coli Sure cells harboring plasmid pLM211-1 containing the bceD gene. Lane 1, molecular mass standards; lane 2, protein cell extract obtained before IPTG induction; lane 3, protein cell extract obtained after IPTG induction; lane 4, His₆-BceD protein eluted from a Ni²⁺-NTA affinity chromatography column. (b) pH dependence of His₆-BceD phosphatase activity using 10 mM of PNPP as substrate. (c) Phosphatase activity of the His₆-BceD protein in the presence of increasing concentrations of the substrate PNPP at pH 6.5.