D-amino acid oxidase
Regulation
Regulation
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Bassoon protein and pLG72, are the current known proteins to physically interact and modulate human DAAO. plG72 is the product of the primate\-specific G72 gene, and higher levels of both were observed in schizophrenia patients. Interaction of plG72 with hDAAO was observed to cause a time\-dependent inactivation with the oxidase. This is believed to be caused by plG72 binding limiting the amount of the enzyme that is [catalytically](/wiki/Catalysis "Catalysis") competent, and can be negated by the cofactor or any active\-site ligands. The plG72 structure is not fully determined so the specific physical interaction with hDAAO is not completely understood as well. Experiments with the basson protein and hDAAO has resulted with a decrease in enzymatic activity similar to plG72\. Researchers suspect the bassoon protein prevents D\-Serine depletion particularly in the [presynaptic](/wiki/Presynaptic "Presynaptic") neuron.

Additionally, researchers focused on compounds that could act as hDAAO inhibitors. Over 500 different compounds have been observed in vitro/in vivo to act as inhibitors on the oxidase and most of them do by [competitive inhibition](/wiki/Competitive_inhibition "Competitive inhibition"). All of these compounds have two similar, main portions. The first portion is the planar portion which interacts with the active site of hDAAO. The planar site’s chemical structure is formed by one or two fused [rings](/wiki/Cyclic_compound "Cyclic compound") and must have a negatively charged [carboxylic](/wiki/Carboxylic_acid "Carboxylic acid") group. The second portion is the [substrate](/wiki/Substrate_%28biochemistry%29 "Substrate (biochemistry)") chain, which can participate in the active zone or entrance of the enzyme. Furthermore, the different compounds are divided into multiple categories (classical, novel, second generation, third generation) depending on the chemical structures. An example of a compound is [benzoate](/wiki/Benzoate "Benzoate"), which is a classical inhibitor. The carboxylic group of benzoate interacts with Arg238, and the aromatic interacts with Tyr224 on the active zone of the oxidase.


Can other proteins interact with human DAAO besides plG72 and bassoon?