Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The authors have studied the enzymhistochemical and ultrastructural pictures of tenocytes of adult human tendons. High succinate dehydrogenase, cytochrome oxidase, TPN-diaphorase, lactate dehydrogenase and glucose-6-phosphate dehydrogenase activity were found, as indicated both oxidativ, anaerobic and pentose-phosphate shung activity. Phosphorylase and glutamate dehydrogenase activity was medial, lipase and alcaline phosphatase activity was slight. In tenocytes well developed rough endoplasmic reticulum and GOLGI apparatus, large amount of free ribosomes were found.
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PMID:Histochemical and ultrastructural study of adult human tendon. 23 84

When malic enzyme is added to a mixture of malate-2-d, TPN, CO2, pyruvate, and TPNH at concentrations calculated to be at equilibrium, the TPNH level first drops and then increases slowly to its original level. This equilibrium perturbation is caused by slower cleavage of C-D than C-H bonds during hydride transfer as malate-2-d and TPNH are partly converted into TPND and malate-2-h in the process of establishing isotopic equilibrium. With malate-2-d, isotope effects for malic enzyme at pH 7.1 and malate dehydrogenase at pH 9.3 of 1.45 and 1.70-2.16 (depending on oxaloacetate level) were determined with this method, while the corresponding isotope effects on V/Kmalate and V for the chemical reactions were 1.5-1.8 and 1.0, and 1.9 and 1.5 for the two enzymes. The advantage of this method is its extreme sensitivity, and the lack of interference from various artifacts. The sensitivity is sufficient to permit determination of 13C and 15N isotope effects in favorable cases, and values of 1.031 for malic enzyme with 13CO2, and 1.047 for glutamate dehydrogenase with 15NH4+ have been determined. In the course of this work it was discovered that the equilibrium constants for oxidation by DPN, and oxidative decarboxylation by TPN are lower for malate-2-d than for malate-2-h by a factor of 0.76-0.82. Changes in Keq upon deuterium substitution, which are predicted by the calculations of Hartshorn and Shiner (1972), should be observed for many other reactions as well.
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PMID:Equilibrium perturbation by isotope substitution. 119 42

A combination of kinetic and isotope effect studies in the presence and absence of the effectors ADP and GTP was used to elucidate the mechanism of regulation of bovine liver glutamate dehydrogenase. ADP at low concentrations of glutamate competes with TPN for free enzyme. GTP exhibits a similar effect at high concentrations (100 microM and above). When ADP binds at its allosteric site, it increases the off rates of both alpha-ketoglutarate and TPNH from their product complexes. This results in a decrease in V/K for both substrates, an increase in V, and an increase in the deuterium isotope effects for all three parameters so that they are all about 1.3. The rate of release of glutamate from E-TPNH-glutamate is also apparently enhanced since no substrate inhibition by glutamate is observed in the presence of ADP. The effect of GTP is in opposition to that of ADP in that GTP decreases the off rates for both TPN and glutamate from E-TPN-glutamate as well as the off rates for alpha-ketoglutarate and TPNH. This results in an increase in the V/K's for both substrates, a decrease in V, and a decrease in the deuterium isotope effects for all three parameters to a value of 1. Substrate inhibition by glutamate is also eliminated by GTP probably by preventing any significant accumulation of E-TPNH to which glutamate binds as an inhibitor.
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PMID:Kinetic studies to determine the mechanism of regulation of bovine liver glutamate dehydrogenase by nucleotide effectors. 612 Jul 19

Histochemical studies have been made of the isocitrate dehydrogenase, succinic dehydrogenase, malate dehydrogenase, glutamate dehydrogenase, DPN diaphorase, TPN diaphorase, delta 5-3 beta-hydroxysteroid dehydrogenase and monoamine oxidase in the caput, corpus and cauda epididymides of normal and alpha chlorohydrin (6.5 mg/kg/9 days) treated rats. Administration of alpha chlorohydrin in a low dose caused a conspicuous decrease in all these enzymes except delta 5-3 beta-HSD, in various cell types of epididymal epithelium and sperms. Biochemical estimations of isocitrate dehydrogenase, succinic dehydrogenase, malate dehydrogenase and delta 5-3 beta-HSD have further supported and confirmed these histochemical observations. These changes in enzyme activities after treatment with low dose of alpha chlorohydrin strongly suggest that TCA cycle and amino acid metabolism of epididymis become defective, much earlier before any histological damage to the epididymis becomes visible.
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PMID:Effects of low doses of alpha chlorohydrin on the dehydrogenases and oxidases of rat epididymal epithelium and sperms: a correlative histochemical and biochemical study. 694 44