Purification and Characterization of Recombinant Methyl Parathion Hydrolase from Pseudomonas aeruginosa HS-D38

Organophosphate hydrolase plays an important role in the bioremediation of organophosphate chemicals contaminating the environment. In this study, some characteristics of recombinant methyl parathion hydrolase (MPH) cloned from Pseudomonas aeruginosa HS-D38 were investigated. The optimum conditions of the MPH reaction were determined i.e. 30 degrees C, pH 10.0. Some metal ions such as Zn2+, Fe3+, Cr2+ and Co2+ activated the activity whereas others, including Cu2+, K+ and Mg2+, inhibited it. SDS-PAGE analysis indicated a molecular weight of 35 kDa for the recombinant MPH protein and the enzyme activity was two-fold higher compared to that in the wild-type strain.