Creative Enzymes stands out with the most advanced equipment, rich experiences and a skillful team, to ensure the high quality and accuracy of the enzyme activity measurement, especially for glutamate dehydrogenase.

Glutamate dehydrogenases (EC 1.4.1.2, EC 1.4.1.3, EC 1.4.1.4, GDHs) are the metabolic enzymes that catalyze the reversible oxidative deamination of L-glutamate to α-ketoglutarate (α-KG) and ammonia, with the concomitant reduction of NAD(P)⁺ to NAD(P)H. Glutamate dehydrogenases can be found in almost every organism, and they are mainly located in the mitochondria, although it was reported that glutamate dehydrogenases can also be present in the cytoplasm, endoplasmic reticulum and nucleus. However, the functions of these enzymes which are outside the mitochondria have not been understood clearly. Glutamate dehydrogenases are the members of the amino-acid dehydrogenase enzyme super-family, which has considerable potential in the production of novel nonproteinogenic amino acids for the pharmaceutical industry. The systematic name of glutamate dehydrogenase is L-glutamate:NAD(P)⁺ oxidoreductase (deaminating).

Glutamate dehydrogenases link amino-acid metabolism to the tricarboxylic acid (TCA) cycle by converting L-glutamate to α-KG, whereas the reductive amination reaction supplies nitrogen to several biosynthetic pathways. Additionally, glutamate dehydrogenase’s activation by leucine facilitates the conversion of GDP to GTP, leading to the activation of the small GTPase Rag, which activates mammalian target of rapamycin complex, and leads to cell growth and decreased autophagy. Apart from the cellular carbohydrate metabolism, glutamate dehydrogenase s are involved in ureagenesis. For instance, the conversion of glutamate into α-KG also produces NH₃⁺, which can be used to form carbamoyl phosphate for the urea cycle. Ultimately, the activities of glutamate dehydrogenases are increased in different brain pathologies, such as schizophrenia, brain cancer and Parkinson’s disease. It is speculated that the increased activity of these enzymes can probably damage neuronal cells. Since glutamate dehydrogenases are at the crossroads of various and multiple important metabolic pathways, a tight monitoring of their activity is thought to be essential.

Figure: The crystal structure of glutamate dehydrogenase from Thermotoga maritima.
PDB: 1B26

Either NAD⁺ or NADP⁺ is the cofactor needed by glutamate dehydrogenases, and thus the enzymes vary based on their cofactor preference: NAD⁺ specificity (EC 1.4.1.2), NADP⁺ specificity (EC 1.4.1.4) or dual cofactor specificity (EC 1.4.1.3). All of these three classes can play an important role in medical and pharmaceutical industries. For example, glutamate dehydrogenases have a crucial function in the differential diagnosis of liver disease and the levels of the liver damage. They can be used to discriminate between acute viral hepatitis and acute toxic liver necrosis and acute hypoxic liver disease. Furthermore, glutamate dehydrogenases can also be the biological indicators for drug safety. Therefore, glutamate dehydrogenases should receive more and more attention not only because of their roles in multiple metabolic pathways, but also the vital functions in many fields. Hence the catalytic activities of the enzymes must be performed necessarily, precisely and rapidly. Creative Enzymes is competent to offer the most reliable quantification of glutamate dehydrogenase activity using spectrophotometric assays. Our utmost-quality assay service has been commended by countless customers. We establish exclusive and reliable enzyme activity assays to stand out in the marketplace. In short, Creative Enzymes is your unique choice for the development of products containing glutamate dehydrogenases.