Enhancing the reactivity of a P450 decarboxylase with ionic liquids

Abstract

The cytochrome P450 family of enzymes have been shown to be powerful biocatalysts for a wide range of selective transformations. However, the industrial uptake of P450 enzymes has been low due to issues with enzyme stability and the requirement for exogenous cofactors to drive the reaction. Herein we describe a facile and scalable method for the stabilisation and solubilisation of a P450 decarboxylase enzyme in ionic liquids. The utilisation of ionic liquids allowed for solubilisation of the relatively water-insoluble fatty acid substrate of the enzyme and the modified enzyme was found to be significantly more thermally stable in ionic liquids relative to the enzyme in aqueous media. The shift to non-aqueous solvent allowed for the enzyme to operate in the V_max region, which when coupled with the improved thermal stability, ultimately resulted in a 1000-fold increase in the process intensity of fatty acid decarboxylation. A novel photochemical method for driving the reaction was also discovered which removed the requirement for exogenous H₂O₂ to be added to the reaction. These results highlight the potential of this strategy as it facilitates a holistic process of biocatalysis engineering where by solvent consideration and increased thermal stability significantly broadens the capability of the enzyme, crucial for the wider realization of industrial biocatalysis.