PEGylation of cytochrome P450 enhances its biocatalytic performance for pesticide transformation

Pesticide intoxication is a major public health concern, and unfortunately there is not an effective treatment for severe organophosphorus pesticide intoxication. In this work, a non-immunogenic enzymatic bioconjugate based on cytochrome P450 was assayed for organophosphorus pesticide transformation. Enzyme therapy is an alternative approach to inactivate pesticides in the bloodstream, transforming them into less toxic metabolites. A variant of cytochrome P450 (CYPBM3 F87A) from Bacillus megaterium was chemically modified with polyethylene glycol. The PEGylated enzyme showed enhanced pesticide transformation activity when compared with the unmodified protein. The transformation rates were higher than those obtained with the unmodified enzyme for all six pesticides transformed. The specific activity of PEGylated preparation for parathion and dichlorophen was up to 9-times higher than these obtained with the unmodified enzyme. In addition, the modified CYP (CYP-PEG) remained active at extremely high pHs, maintaining 90% of its maximal activity at pH 11, as opposed to the unmodified CYP that retained less than 20% of its maximal activity at that pH. In addition, the bioconjugate showed good catalytic activity in blood serum and innocuousness on immune cells. The potential use of PEGylated CYP as a detoxification strategy for pesticide poisoning is demonstrated and discussed.