Description
L-glutamate oxidase (EC 1.4.3.11) is an enzyme that catalyzes oxidative deamination of the α-amino group of L-glutamate to 2-ketoglutarate, with concomitant reduction of molecular oxygen and water to ammonia and hydrogen peroxide. L-glutamate oxidase is a member of the general oxidoreductase family, which catalyzes the CH-OH group of the substrate and uses NAD+ or NADP+ as the cofactor.
The systematic name of this enzyme class is L-glutamate:oxygen oxidoreductase (deaminating), which is also called glutamate (acceptor) dehydrogenase, glutamate oxidase, glutamic acid oxidase, glutamic dehydrogenase (acceptor) or L-glutamic acid oxidase. L-glutamate, the substrate of the reaction catalyzed by L-glutamate oxidase, has a flavor-enhancing property that creates the sensation of “umami”, and the monosodium salt of L-glutamate is widely used as a seasoning for cooking and as a food additive.
Moreover, L-glutamate is also the principal excitatory neurotransmitter in the brain. Furthermore, the excessive release of this amino acid may play a pivotal role in the neuronal death associated with different neurological disorders. Therefore, L-glutamate and L-glutamate oxidase play important roles in the fields of food production and clinical biochemistry.
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Specifications |
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| Appearance | Lyophilized powder |
| Contents | 25 units/vial |
| Source | E. coli |
| Molecular weight | 140 kDa |
| Subunit structure | α2β2γ2(α: 43,000, β: 17,000, γ: 10,000) |
| Thermo stability | stable below 60°C (30 min at pH 6) |
| pH stability | pH 4-10 (60 min at 50ºC) |
| Optimum pH | pH 7-9 |
| Km | 0.2 mM |
| Substrate specificity | L-Glu 100%; L-Gln 0%; L-Asp 0%; D-Glu 0%; 0% for 16 other L-amino acids |
| Unit definition | One unit equals the amount of enzyme that liberates 1 micromole 2-ketoglutarate per minute with 3-methyl-2- benzothiazolone hydrazone hydrochloride as substrate at 30°C, pH 7.4 (Soda K, et al. 1968). |
| Reaction | L-Glutamate + O2 + H2O ---> alpha-Ketoglutarate + NH3 + H2O2 |
| Cofactor | FAD (2 mol per mol of enzyme) |
Storage and Stability
Lyophilized powder may be stored desiccated at 4°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Prepare fresh before use.
References
1.Arima, J. et al., J. Biochem. 134, 805-812(2003)
