A Diffusion-Reaction Model for One-Pot Synthesis of Chemicals with Enzyme Cascades

摘要

We propose a kinetic model for one-pot synthesis of chemicals using enzyme cascades with an explicit consideration of mass transport and local concentration changes. The kinetic model was discussed in the context of a two-enzyme cascade system composed of glucose oxidase (GOx) and horseradish peroxidase (HRP). The simulation results indicate that proximity between enzymes has no visible effects on the reaction rate for cascades freely diffusing in a solution, while the initial reaction rate of a colocalized enzyme cascade can be profoundly affected by resistance of mass transport within a supporting matrix. The kinetic model was applied to a one-pot synthesis using GOx-catalase (Cat) cascade in overcoming the unfavourable pH changes caused by product accumulation. The simulation results indicate that, by optimizing the enzyme composition and by enhancing intermediate transport, the GOx-Cat cascade is able to increase the efficiency of substrate conversion to near 100 % while the reaction time can be greatly shortened.