DAO
DAO (D-amino acid oxidase, also known as DAMOX or DAAO) is a flavoprotein oxidoreductase that catalyses the oxidative deamination of D-amino acids. It helps clear D-amino acids from diet, gut bacteria and endogenous synthesis, and regulates D-amino acid neurotransmitters in the brain. Browse Assay Genie's current range of DAO research reagents below, or read on for the biology behind the target.
DAO catalyses the oxidative deamination of D-amino acids and has broad substrate specificity. It is needed to catabolise D-amino acids that are made endogenously, come from gastrointestinal bacteria or are obtained from the diet, so that they can be used as nutrients. In the brain it regulates D-amino acid neurotransmitters such as D-serine, a co-agonist of N-methyl D-aspartate (NMDA) receptors, and may therefore modulate synaptic transmission.
The enzyme also catalyses the first step of the racemisation of D-DOPA to L-DOPA, for possible use in an alternative dopamine biosynthesis pathway, and the first step of the chiral inversion of N(gamma)-nitro-D-arginine methyl ester (D-NNA) to L-NNA, a nitric oxide synthase inhibitor. The hydrogen peroxide produced in the reaction contributes to the oxidative killing activity of phagocytic leukocytes and protects against bacterial colonisation of the small intestine. Enzyme secreted into the intestinal lumen may not be catalytically active and could instead be cleaved proteolytically into peptides with antimicrobial activity. Hydrogen peroxide from this reaction may also promote cellular senescence in response to DNA damage.
The DAO gene encodes a peroxisomal flavoprotein that uses flavin adenine dinucleotide (FAD) as its prosthetic group. It acts on a wide variety of D-amino acids but is inactive on naturally occurring L-amino acids. UniProt places the protein in the DAMOX/DASOX family and records localisation to the peroxisome matrix, cytosol, presynaptic active zone and secreted pool. Its overall biological function is not fully defined; it may act as a detoxifying agent that removes D-amino acids accumulating during ageing. In mice it degrades D-serine, and the gene may play a role in the pathophysiology of schizophrenia.
DAO regulates D-serine, a co-agonist of NMDA receptors, so it is studied in relation to synaptic transmission and D-amino acid neurotransmitters in the brain.
The DAO gene may play a role in the pathophysiology of schizophrenia, linking D-serine degradation to NMDA receptor function.
Hydrogen peroxide from DAO activity contributes to oxidative killing by phagocytes and protects against bacterial colonisation of the small intestine.
DAO may remove D-amino acids that accumulate during ageing, and its hydrogen peroxide may promote senescence after DNA damage.
DAO catalyses the oxidative deamination of D-amino acids, with broad substrate specificity. This lets cells catabolise D-amino acids from the diet, gut bacteria or endogenous synthesis, and it regulates brain D-serine. The reaction produces hydrogen peroxide, which supports antimicrobial defence.
DAO is the HGNC symbol for D-amino acid oxidase. Aliases include DAMOX and DAAO, and UniProt names the protein D-amino-acid oxidase. Its enzyme classification is EC 1.4.3.3, and it belongs to the DAMOX/DASOX family of flavoproteins.
Mouse and rat both have a Dao ortholog. In mice the enzyme degrades D-serine, a co-agonist of the NMDA receptor. The human gene may play a role in the pathophysiology of schizophrenia; check the datasheet of any product for its validated reactivity.
Other D-amino acid metabolism enzymes, NMDA receptor pathway components and oxidative stress markers with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P14920; product specifications from Assay Genie datasheets.