D-Aminoacid oxidase

D-Aminoacid oxidase has been isolated from a nnmber of yeasts, and the nucleotide sequence of the enzyme from Rhodotorula gracilis ATCC 26217 has been established (Alonso et al. 1998). The gene could be overexpressed in Escherichia coli, and levels of the enzyme were greater under conditions of low aeration the enzyme isolated from the recombinant organisms was apparently the apoenzyme since maximum activity required the presence of FAD. 

Abstract G72 and G30 constitute a pair of primate-specific genes on complementary strands of human chromosomal 13q33. G72 is proposed to encode a protein that can activate D-amino acid oxidase (DAAO), therefore, named as D-aminoacid oxidase activator (DAOA) (Chumakov et al., 2002). This hypothesis about G72 and DAAO requires substantial further proof (see discussion later), and the neutral name G72 will be used here, although DAOA is widely used in the literature now. The G72/ G30 gene is, at this time, one of the best supported loci for both schizophrenia (SZ) and bipolar disorder (BD) by independent datasets (Craddock et al., 2006 Detera-Wadleigh and McMahon, 2006). Here, we will describe the discovery of gene complex G72/G30, association studies with SZ and BD with a meta-analysis, as well as brief information about the biology of G72/G30. 

List of Abbreviations CD/MRV, Common Disease/Multiple Rare Variants DAAO, D-amino acid oxidase DAOA, D-aminoacid oxidase activator EST, expression sequence tag GEO, Gene Expression Omnibus MAF, minor allele frequency NIMH, National Institute of Mental Health NMDA, N-methyl D-aspartate RT-PCR, reverse transcription-PCR... 

E D-aminoacid oxidase, immobilized enzyme from Trigonopsis variables... 

Inhibits catecholase, D-aminoacid oxidase, fatty acid synthesis, lipolysis, nicotinamide deaminase, NMN aminhydrolase, phenol oxidase, tributyrinase. 

One of the main problems of oxidases is the equimolar production of hydrogen peroxide as a side-product that can inactivate them or alter its substrate. Thus, the elimination of this compound seems to be a must. Although some metals may destroy hydrogen peroxide, they can also produce some undesired modifications of enzymes or compounds, therefore milder and more selective agents should be preferred. In this sense, the use of catalase (EC 1.11.1.6) is an adequate solution since this enzyme specifically destroys the hydrogen peroxide without producing any other side-reaction. The combined use of oxidases and catalase is then a good solution, as illustrated in Fig 6.4.1. When the enzyme D-aminoacid oxidase is used alone (a), the reaction mainly produces undesired phenylacetic acid, but when used... 

More recently we have studied the effects of j3-thia-proline on protein synthesizing systems(56). -Thiapro-line,first synthesized by Eourneau et al. (57) ilia-S not been assayed in biological systems. We have obtained preliminary data indicating that it is a substrate for hog kidney D-aminoacid oxidase and for rat liver mitochondria proline oxidase,two enzymes active on y-thiaproline. 

The first to be isolated of those complexes which enzymes form with their substrates was the complex of D-alanine, D-aminoacid oxidase, and its co-factor FAD (riboflavine adenine dinucleotide). It consisted of hexagonal purple crystals and was stable in the absence of air. Electron spin resonance measurements showed that the co-factor, present in these crystals, was in its free-radical monohydro-form (FADH) (Yagi, 1965). 

It is very important to assay the essential amino acids in food and feeds for their nutritional value. To obtain the most reliable analytical information, an electrometric method based on amperometric biosensors122123 was adopted. Because of the reliability assured, the amperometric biosensors can be integrated in an amperometric FIA system.123 For the assay of aminoacids it is very important to discriminate the l- and D-amino acids. Constructed amperometric biosensors based on L-aminoacid oxidase and D-amino acid oxidase can discriminate the l- and D-amino acids.124 125 For this purpose, these electrometric methods assure the best reliability of the analytical information as a result of the simplicity of sampling process, and because of the possibility of assaying the enantiomers without prior separation from the matrix. 

En prince A adde hemoique, qui cst un inhibiteur sp ifique de la D-aminoacide-oxydase et de la glycine-oxidase, le tissu bdpatique... 

Trackman, P. C., Pratt, A. M., Wolanski, A., Tang, S.-S., Offer, G. D., Troxler, R. F., and Kagan, H. M., 1990, Cloning of rat lysyl oxidase cDNA complete codons and predicted aminoacid sequences. Biochemistry 29 4863ii4870. 

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