Designer oleosomes as efficient biocatalysts for enhanced degradation of organophosphate nerve agents

Abstract

Engineering enzymes with higher activities, stabilities and reusabilities has been constantly pursued for applications of enzymatic catalysis in industrial, pharmaceutical and environmental processes. We report here a novel approach to prepare efficient biocatalysts in vivo for enhanced degradation of organophosphate nerve agents. Organophosphorus hydrolase (OPH) was genetically fused with oleosins to form oleosome-based biocatalysts. Quick purification of intact OPH-associated oleosomes can be achieved by using a flotation centrifugation method due to the high triacylglycerol (TAG) content in the oleosomes, making it easy for further protein recovery and reuse. The newly developed biocatalysts exhibited a 5-fold increase in the degradation rate against paraoxon compared to free OPH. In addition, the thermal stability and solvent tolerance were also enhanced remarkably. More importantly, the resulting biocatalysts remained intact and active even after repeated recycling, suggesting their potential use for bio-catalytic decontamination of organophosphate neurotoxins.