NAD (H) Linked Enzyme Catalyzed Reactions using Coupled Enzymes in a Composite Nanoparticle System

Different approaches for cofactor recycling/regeneration have been studied and one of them is having regenerating enzyme immobilized on some suitable support. Here, we are reporting the cofactor NAD (H) recycling with the help of free enzymes and enzymes loaded on nanoparticles. Baker’s yeast alcohol dehydrogenase (ADH) and formate dehydrogenase (FDH) from Candida boidinii were immobilized on alumina nanoparticles and applied to catalyze the coupled reactions for production of n-propanol. Cofactor regeneration within the reaction cycle was achieved as a result of collision between enzyme loaded particles and free cofactor. Brownian motion provided effective interactions among the catalytic components, and thus realized a dynamic shuttling of the cofactor between the two enzymes to keep the reaction cycles continuing. Maximum recycle rate of 6650 cycles/hr was obtained and it decreased with increasing cofactor concentration within the reaction system, for free as well as immobilized system.It was concluded that particles attached enzymes could be one of the new biochemical strategy used for cofactor dependent biotransformation.