D-Amino acid oxidase (DAO or DAAO) is a flavin adenine dinucleotide (FAD)-containing flavoproteins that catalyse the oxidative deamination of d-amino acids with oxygen to generate the corresponding 2-oxo acids along with hydrogen peroxide and ammonia. It displays broad substrate specificity and acts on several neutral and basic d-amino acids, such as d-Ser and d-Ala [].
Members of this family function as activators of D-amino acid oxidase. This enzyme catalyzes the oxidative deamination of D-3,4-dihydroxyphenylalanine (D-DOPA) and D-serine - a precursor of dopamine and a participant in glutamatergic transmission, respectively []. Variation in the DAO activator gene have been associated with bipolar disorder and major depression [], although other studies have cast doubt on such a link [].
