Glycine dehydrogenase (decarboxylating)


Glycine decarboxylase also known as glycine cleavage system P protein or glycine dehydrogenase is an enzyme that in humans is encoded by the GLDC gene.

Reaction

Glycine decarboxylase is an enzyme that catalyzes the following chemical reaction:
Thus, the two substrates of this enzyme are glycine and H-protein-lipoyllysine, whereas its two products are H-protein-S-aminomethyldihydrolipoyllysine and CO2.
This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-NH2 group of donors with a disulfide as acceptor. This enzyme participates in glycine, serine and threonine metabolism. It employs one cofactor, pyridoxal phosphate.

Function

Glycine decarboxylase is the P-protein of the glycine cleavage system in eukaryotes. The glycine cleavage system catalyzes the degradation of glycine. The P protein binds the alpha-amino group of glycine through its pyridoxal phosphate cofactor. Carbon dioxide is released and the remaining methylamine moiety is then transferred to the lipoamide cofactor of the H protein.
Degradation of glycine is brought about by the glycine cleavage system, which is composed of four mitochondrial protein components: P protein, H protein, T protein, and L protein.

Clinical significance

is due to defects in GLDC or AMT of the glycine cleavage system.