Aspartate dehydrogenase () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are L-aspartic acid, water, and oxidised nicotinamide adenine dinucleotide (NAD<sup>+</sup>}. Its products are oxaloacetic acid, ammonia, reduced NADH, and a proton. Nicotinamide adenine dinucleotide phosphate can be used as an alternative cofactor.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is L-aspartate:NAD(P)+ oxidoreductase (deaminating). Other names in common use include NAD-dependent aspartate dehydrogenase, NADH2-dependent aspartate dehydrogenase, and NADP+-dependent aspartate dehydrogenase. This enzyme participates in nicotinate and nicotinamide metabolism.
As of late 2007, only one structure has been solved for this class of enzymes, with the PDB accession code .