Real-time and simultaneous assay of monophenolase and diphenolase activity in tyrosinase catalyzed cascade reactions by combination of three-way calibration and excitation-emission matrix fluorescence.

A real-time assay for multiple enzyme activities in cascade reactions is required for research on metabolism and bioengineering. Tyrosinase has the bifunctional activity of monophenolase and diphenolase. A combined strategy of three-way calibration with excitation-emission matrix (EEM) fluorescence was developed for real-time and simultaneous determination of monophenolase and diphenolase activity with tyrosine as a substrate.