Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.1.4 (glutamate dehydrogenase)
 4,358 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A direct enzymatic micromethod (sample volume, 3mul) has been adapted to the centrifugal analyzer (ENI-GEMSAEC) for measurement of urea in plasma and urine. The method is based on urease (urea amidohydrolase, EC3.5.1.5)/glutamate dehydrogenase [l-glutamate:NAD(P)+oxidoreductase (deaminating), EC1.41.3] coupled reactions, and uses a two-point fixed-time (t(1)=20s,t(2)=50s)kinetic scheme for monitoring the rate of comsumption of NADH at 340 nm. Sensitivity and precision of the method are excellent,and results compare well with those from a commonly used continuous-flow method.
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PMID:Direct enzymatic determination of urea in plasma and urine with a centrifugal analyzer. 97 5

Glial cells transform glucose to a fuel substrate taken up and used by neurons. In the honeybee retina, photoreceptor neurons consume both alanine supplied by glial cells and exogenous proline. Ammonium (NH4+) and glutamate, produced and released in a stimulus-dependent manner by photoreceptor neurons, contribute to the biosynthesis of alanine in glia. Here we report that NH4+ and glutamate are transported into glia and that a transient rise in the intraglial concentration of NH4+ or of glutamate causes a net increase in the level of reduced nicotinamide adenine dinucleotides [NAD(P)H]. Biochemical measurements indicate that this is attributable to activation of glycolysis in glial cells by the direct action of NH4+ and glutamate on at least two enzymatic reactions: those catalyzed by phosphofructokinase (PFK; ATP:D-fructose-6-phosphotransferase, EC2.7.1.11) and glutamate dehydrogenase (GDH; L-glutamate:NAD oxidoreductase, deaminating; EC1.4.1.3). This activation leads to an increase in the production and release of alanine by glia. This signaling, which depends on the rate of conversion of NH4+ and glutamate to alanine and alpha-ketoglutarate, respectively, in the glial cells, raises the novel possibility of a tight regulation of the nutritive function of glia.
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PMID:Ammonium and glutamate released by neurons are signals regulating the nutritive function of a glial cell. 906 99

In our experiments, inactivation of lactate dehydrogenase (LDH, EC1.1.1.27) in the presence of human microtubule-associated tau is observably suppressed during thermal and guanidine hydrochloride (GdnHCl) denaturation. Kinetic studies show tau can prevent LDH from self-aggregation monitored by light scattering during thermal denaturation. On the other hand, neuronal tau promotes reactivation of LDH and suppresses self-aggregation of non-native LDH when GdnHCl solution is diluted. Furthermore, the reactivation yield of LDH decreases significantly with delayed addition of tau. All experiments were completed in the reducing buffer with 1 mM DTT to avoid between tau and LDH forming the covalent bonds during unfolding and refolding. Thus, Tau prevents proteins from misfolding and aggregating into insoluble, nonfunctional inclusions and assists them to refold to reach the stable native state by binding to the exposed hydrophobic patches on proteins instead of by forming or breaking covalent bonds. Additionally, tau remarkably enhances reactivation of GDH (glutamic dehydrogenase, EC 1.4.1.3), another carbohydrate metabolic enzyme, also showing a chaperone-like manner. It suggests that neuronal tau non-specifically functions a chaperone-like protein towards the enzymes of carbohydrate metabolism.
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PMID:Chaperone-like manner of human neuronal tau towards lactate dehydrogenase. 1553 42

The activities of nitrate reductase (EC1.6.6.1), nitrite reductase (EC 1.6.6.4), glutamine synthetase (EC6.3.1.2), glutamate synthase (EC1.4.7.1) and NAD(P)H-dependent glutamate dehydrogenase (EC 1.4.1.3) were investigated in mesophyll and bundle sheath cells of maize leaves (Zea mays L.). Whereas nitrate and nitrite reductase appear to be restricted to the mesophyll and GDH to the bundle sheath, glutamine synthetase and glutamate synthase are active in both tissues.During the greening process, the activities of nitrate and nitrite reductase increased markedly, but glutamine synthetase, glutamate synthase and glutamate dehydrogenase changed little.
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PMID:The localisation of enzymes of nitrogen assimilation in maize leaves and their activities during greening. 2441