In enzymology, tartrate dehydrogenase () is an enzyme that catalyzes the chemical reaction
The two substrates of this enzyme are meso-tartaric acid and oxidised nicotinamide adenine dinucleotide (NAD<sup>+</sup>). Its products are 2-hydroxy-3-oxosuccinic acid, reduced NADH, and a proton. The enzyme can also act on the stereoisomer (+)-tartaric acid, giving the same product.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD<sup>+</sup> or NADP<sup>+</sup> as acceptor. The systematic name of this enzyme class is tartrate:NAD<sup>+</sup> oxidoreductase. This enzyme is also called mesotartrate dehydrogenase. This enzyme participates in glyoxylate and dicarboxylate metabolism. It employs one cofactor, manganese.