Thermal compartments for efficient coupling of thermally incompatible enzymes into Cascade reactions via plasmonic photothermal conversion in hydrogels

The use of biocatalysis in the green synthesis of industrial chemicals via multi-enzyme cascade reactions is a key development in the transition to a sustainable future. Incompatibility of reaction conditions for different enzymes remains a clear challenge to implementation of coupled cascade reactions. Compartmentalization of immobilized enzymes has been demonstrated to allow the optimization of pH, electrolyte composition, and solvent conditions independently, allowing improved performance. To date, temperature has remained a challenge and isothermal requirements for the cascades have limited the range of enzymes that can be coupled. Here, we demonstrate a system for thermal compartmentalization in a one-pot system allowing thermally incompatible enzymes to work in different thermal environments. We include metallic nanoparticles into a hydrogel compartment system, then apply plasmonically enabled local photothermal conversion to pattern temperature to allow two compartments with enzymes operating at very different temperatures. As proof of principle, we couple a thermostable alcohol dehydrogenase to a moderate reductive aminase as a representative low temperature enzyme to synthesize chiral amines as relevant precursors for the synthesis of active pharmaceutical ingredients. This study will allow new combinations of enzymes with the potential to improve current processes or enable currently unsolved challenges in enzyme-based green synthesis.