[Expression and characterization of a novel cytochrome P450 enzyme from Variovorax paradoxus S110]

Cytochrome P450 monooxygenases as powerful biocatalysts catalyze a wide range of chemical reactions to facilitate exogenous substances metabolism and biosynthesis of natural products. In order to explore new catalytic reactions and increase the number of P450 biocatalysts used in synthetic biology, a new self-sufficient cytochrome P450 monooxygenase (P450(VpMO)), belongs to CYP116B class, was mined from Variovorax paradoxus S110 genome and expressed in Escherichia coli. Based on characterization of the enzymatic properties, it shows that the optimal pH and temperature for P450(VpMO) reaction activity are 8.0 and 45 °C, respectively. P450(VpMO) is relatively stable at temperatures below 35 °C. The Km and kcat of P450(VpMO) toward 4-Methoxyacetophenone are 0.458 mmol/L and 2.438 min⁻¹, respectively. Importantly, P450(VpMO) was able to catalyze the demethylation reaction for a range of substrates containing methoxy group. Its demethylation reactivity is reasonably better than other P450s belongs to CYP116B class, particularly, for 4-methoxyacetophenone with a great conversion efficiency at 91%, showing that P450(VpMO) could be used as a great biocatalyst candidate for further analysis.