Enzyme Activity Measurement for L-Glutamate Oxidase

Creative Enzymes has emerged as a worldwide leader in the development of enzyme activity assays. We provide services of enzyme activity measurement with the utmost quality that exceeds the average level in the industry. The professional processes and advanced techniques of Creative Enzymes support researchers in various activity assays for oxidoreductases, including L-glutamate oxidase.

L-glutamate oxidase (EC 1.4.3.11) is an enzyme that catalyzes the oxidative deamination of the α-amino group of L-glutamate to 2-ketoglutarate, with the concomitant reduction of the molecular oxygen and water to ammonia and hydrogen peroxide. This enzyme was originally derived from an aqueous extract of a wheat bran culture of Streptomyces sp. X-119-6, and several kinds of this enzyme have been later identified from the genus Streptomyces. 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 activity 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 plays an important role in the fields of food production and clinical biochemistry, so does the L-glutamate oxidase.

Owning to the high substrate specificity and high stability of L-glutamate oxidase from Streptomyces sp. X-119-6, it becomes a commercially available enzyme that is used as a biosensor. In addition, a unique feature of L-glutamate oxidase from Streptomyces sp. X-119-6 is that it has a hexameric structure, which consists of two α chains, two β chains and two γ chains with subunit molecular weights of approximately 44 kDa, 19 kDa and 9 kDa respectively.

Figure: The crystal structure of L-glutamate oxidase from Streptomyces sp. X-119-6.
PDB: 2E1M

Despite such importance of L-glutamate oxidase, the activity measurement of this enzyme has not been well developed using spectrophotometric assays, although other methods have been reported before. The spectrophotometric assay is considered a reliable and cost-effective method for activity quantification. Fortunately, Creative Enzymes is proud to offer the accurate activity assay for L-glutamate oxidase, based on our extensive experiences in studying the enzyme and optimizing the method. Our products are the most trusted and proven, resulting in a high rate of repeat sales. Our passion for high quality and unique service is only exceeded by our excellent reputation in the global marketplace.