FAD-mediated enzymatic conversion of NAD+ to NADH: application to chiral synthesis of L-lactate.

Electroenzymatic reduction of NAD+ to NADH for subsequent use in enzymatic synthesis has been carried out at carbon electrodes bearing lipoamide dehydrogenase (LiDH) immobilized under a Nafion film. The self-mediated electron transfer was made possible by an excess of flavin adenine dinucleotide (FAD) entrapped together with LiDH. Results were compared to those obtained with a similar electrode containing both LiDH and a polymeric form of FAD (pFAD) prepared by anodic polymerization of FAD.