Glycine oxidase (GO)

Glycine oxidase (EC 1.4.3.19) is a flavoprotein enzyme that catalyzes the oxidative deamination of glycine into glyoxylate, ammonia, and hydrogen peroxide. While historically identified in bacteria like Bacillus subtilis as part of the thiamine biosynthesis pathway (thiO gene), the term is frequently applied to human D-amino acid oxidase (DAAO) in clinical contexts due to its significant glycine-degrading activity in the liver and brain. It serves as a vital therapeutic target in neuropsychiatry, where inhibiting the enzyme is explored as a strategy to elevate glycine concentrations to modulate N-methyl-D-aspartate (NMDA) receptor function, potentially addressing symptoms of schizophrenia and amyotrophic lateral sclerosis (ALS). In the context of metabolic disorders, glycine oxidase activity is linked to the production of glyoxylate, a direct precursor to oxalate; thus, its inhibition or the targeting of related enzymes like glycolate oxidase (HAO1) is a focus for substrate reduction therapies in Primary Hyperoxaluria. Furthermore, bacterial glycine oxidase is studied as a potential target for novel antimicrobial agents and has been engineered for biotechnological applications, such as the development of herbicide-resistant crops and glycine-sensing biosensors. As a drug target, it represents a multifaceted point of intervention for managing both central nervous system signaling and systemic metabolic flux.

Other names

thiOGlycine:oxygen oxidoreductase (deaminating)D-amino acid oxidase (DAAO)DAOGoxAHydroxyacid oxidase 2 (HAO2)Glycine oxidase 2Glycine dehydrogenase (deaminating)

Inhibition of glycine oxidation to elevate synaptic glycine levels (acting as an NMDA receptor co-agonist) or blockade of the pathway producing glyoxylate and oxalate in metabolic diseases.