Lipoamide dehydrogenase (or diaphorase) catalyzes the following reaction: Lipoamide + NADH + H+ Dihydrolipoamide + NAD+. The enzyme occurs in mammalian and microbial cells and it catalyzes a number of reactions which involve NAD+ or NADH. Lipoamide dehydrogenase from porcine heart contains two polypeptide chains which are similar. It has two molecules of tightly bound flavin adenine dinucleotide (FAD). The molecular weight of the porcine heart enzyme is between 100,000 and 114,000.
