Mechanistic study for catalytic promiscuity of phenylalanine dehydrogenase induced by amino acid deep eutectic solvents

Abstract Catalytic promiscuity of phenylalanine dehydrogenase (NTAaDH) induced by the amino acid deep eutectic solvents (AA‐DES) was studied. The activity of NTAaDH with the L‐Phe‐DES as substrate was 71.7‐fold that of the buffer system, while it was 24.4‐fold for L‐Lys‐DES. The half‐life of NTAaDH was enhanced by threefold of that of buffer at 50°C. Mechanism of catalytic promiscuity induced by AA‐DES was studied. AA‐DES can biomimetic intracellular environment with a crowding effect and provide a protective layer of enzyme. Analysis of the conformation change of NTAaDH indicated the shrinkage of the substrate channel. This study provided a new strategy for the solvent engineering for the oxidoreductases and further for industrial production.