Fig. 5

Electrophoretic analysis of the purified OpdC protein (A). Separation was performed on a 12.5% (w/v) SDS polyacrylamide gel and after was stained with 0.025% Coomassie blue R-250. Lane 1, standard marker; lane 2, crude extract from E. coli BL21 (DE3) containing pET-32( +)/opdC; lane 3, crude extract from IPTG-induced E. coli BL21 (DE3) containing pET-32( +)/opdC; lane 4, purified OpdC protein from Hi-Trap kit (Amersham). pH effect on the relative activity of OpdC (B). The esterase activity of OpdC was assayed using ρ-NPB as substrate at different pH values at 30 ± 0.5 °C for 1 h. Effect of temperature on the relative activity of OpdC (C). The esterase activity of OpdC was assayed using ρ-NPB as substrate at different temperature values at pH 6 for 1 h. Substrate relative activities of OpdC on the various OP insecticides (D). The OP hydrolase activity of OpdC was assayed using as substrate with 200 mg/L OP in insecticides at 35 ± 0.5 °C and pH 6.0 for 12 h. Names of insecticides as the X-axis of the figure shows the abbreviations as follow: OP, organophosphorus; CS, cadusafos; CP, chlorpyrifos; CM, comnaphos; DZ, diazinon; DF, dyfonate; EP, ethoprophos; FA, fenamiphos; MPT, methylparathion; and PT, parathion. Means with different lowercase letters (a-f) indicate significant (p < 0.05) differences of survival rate by Duncan’s multiple range test