PYROXD1 Belongs to the class-I pyridine nucleotide-disulfide oxidoreductase family. In biochemistry, an oxidoreductase is an enzyme that catalyzes the transfer of electrons from one molecule (the reductant, also called the hydrogen or electron donor) to another (the oxidant, also called the hydrogen or electron acceptor). This group of enzymes usually utilizes NADP or NAD as cofactors. Proper names of oxidoreductases are formed as "donor:acceptor oxidoreductase"; however, other names are much more common. The common name is "donor dehydrogenase" when possible, such as glyceraldehyde-3-phosphate dehydrogenase for the second reaction above. Common names are also sometimes formed as "acceptor reductase", such as NAD+ reductase. "Donor oxidase" is a special case where O2 is the acceptor.