Nanoparticles are one of the most attractive supports for biocatalysts in that they offer high surface area-to-volume ratios, easy preparation, versatile surface chemistry and tunable solution and assembling behaviors. Researchers from Dr. WANG Ping's group, Institute of Process Engineering, broaden the application of nanoparticles as immobilization carrier to multienzyme system involving cofactor regeneration.

A coupled reaction catalyzed by glutamate dehydrogenase, glucose dehydrogenase and NADH was realized by magnetic nanoparticle-carried enzymes and cofactor. The particle collision due to Brownian motion of nanoparticles successfully enabled this coupled reaction even when the enzymes and cofactor were immobilized separately onto superparamagnetic nanoparticles. The mobility of the immobilized component was critical to the reaction kinetics of the reaction system. By applying an alternating magnetic field, enhanced reaction rates were obtained. 

These results demonstrated a new and promising approach for the preparation of easily reusable immobilized multienzymic catalysts capable of carrying out predetermined reaction pathways for multi-step biosynthetic applications. 

The work, supported by National Natural Science Foundation of China (Grant No. 20728607, 20706054), and 973 Program (2009CB724705), has been published on the Journal of Biotechnology (2011, 54: 274-280).