In enzymology, glycine dehydrogenase () is an enzyme that catalyzes the chemical reaction
The three substrates of this enzyme are glycine, water, and oxidised nicotinamide adenine dinucleotide (NAD<sup>+</sup>). Its products are glyoxylic acid, reduced NADH, ammonia, and a proton.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH<sub>2</sub> group of donors with NAD+ or NADP+ as acceptor. The systematic name of this enzyme class is glycine:NAD+ oxidoreductase (deaminating).
This should not be confused with:
the glycine dehydrogenase (decarboxylating), which is another name for the glycine cleavage system P-protein ().
or the glycine dehydroganse (cyanide forming) ().
or the glycine dehydrogenase (cytochrome) ().