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)

Isolated membrane fractions of Escherichia coli K-12 yielded complex immunoprecipitate patterns when Triton X-100 and sodium dodecyl sulfate extracts were examined by crossed immunoelectrophoresis with antienvelope immunoglobulins. Twelve of the 46 antigens in the immunoprecipitate patterns of inner (plasma) membranes were identified by zymograms and/or by the use of specific antisera. The following enzyme activities were detected in immunoprecipitates: 6-phosphogluconate dehydrogenase (EC 1.1.1.43); adenosine triphosphatase (EC 3.6.1.3); glutamate dehydrogenase (EC 1.4.1.4), two separate components; malate dehydrogenase (EC 1.1.1.37); dihydroorotate dehydrogenase (EC 1.3.3.1); succinate dehydrogenase (EC 1.3.99.1); lactate dehydrogeanse (EC 1.1.1.27); reduced nicotinamide adenine dinucleotide dehydrogenase (EC 1.6.99.3); protease (EC 3.4.21.1); and glycerol 3-phosphate dehydrogenase (EC 1.1.99.5). The corresponding immunoprecipitate pattern for isolated outer membranes consisted of at least 25 discrete antigens and differed strikingly from that obtained with inner membranes. Two major immunogens were identified as lipopolysaccharide and Braun lipoprotein. A protease-active immunoprecipitate was also detected in this fraction, but attempts to identify the Rosenbusch matrix protein in the crossed immunoelectrophoretic profile were unsuccessful.
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PMID:Immunochemical analysis of inner and outer membranes of Escherichia coli by crossed immunoelectrophoresis. 33 83

Measurements of the deaminating activity of NAD-dependent glutamate dehydrogenase (NAD-GDH) in Pseudomonas aeruginosa strain 8602 (PAC 1) showed an initially constant rate that gave way to a 3.5-fold increased rate on prolonged incubation. Only the faster rate was observed when assay mixtures were preflushed with nitrogen or were treated with the detergent Triton X-100. Comparison of the intracellular distribution of NAD-GDH with marker enzymes showed it to be associated with the cytoplasmic membrane. The results suggest that NAD-GDH may be linked to oxygen through an electron-transport system.
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PMID:NAD-dependent glutamate dehydrogenase from Pseudomonas aeruginosa is a membrane-bound enzyme. 131 Dec 77

Leucine and beta-(+/-)-2-aminobicyclo[2.2.1]heptane-2-carboxylic acid (BCH) stimulated, in a dose-dependent manner, reductive amination of 2-oxoglutarate in rat brain synaptosomes treated with Triton X-100. The concentration dependence curves were sigmoid, with 10-15-fold stimulations at 15 mM leucine (or BCH); oxidative deamination of glutamate also was enhanced, albeit less. In intact synaptosomes, leucine and BCH elevated oxygen uptake and increased ammonia formation, consistent with stimulation of glutamate dehydrogenase (GDH). Enhancement of oxidative deamination was seen with endogenous as well as exogenous glutamate and with glutamate generated inside synaptosomes from added glutamine. With endogenous glutamate, the stimulation of oxidative deamination was accompanied by a decrease in aspartate formation, which suggests a concomitant reduction in flux through aspartate aminotransferase. Activation of reductive amination of 2-oxoglutarate by BCH or leucine could not be demonstrated even in synaptosomes depleted of internal glutamate. It is suggested that GDH in synaptosomes functions in the direction of glutamate oxidation, and that leucine may act as an endogenous activator of GDH in brain in vivo.
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PMID:Activation of glutamate dehydrogenase by leucine and its nonmetabolizable analogue in rat brain synaptosomes. 196 60

The mitoplasts were prepared from bullfrog (Rana catesbeiana) liver mitochondria by treatment with digitonin and were then separated into the matrix and inner membrane fractions. The matrix fraction thus obtained was free of lysosomal contaminations and exhibited a distinct proteinase activity. pH dependency of the matrix proteinase activity measured in the presence and absence of iodoacetamide revealed that the matrix contained at least two kinds of proteinase, a major alkaline thiol proteinase having an optimal pH at 8.5 and a minor neutral proteinase having an optimal pH at 7.5. The major matrix proteinase activity was strongly inhibited by leupeptin, chymostatin, antipain and E64-C, an inhibitor of Ca2+-dependent thiol proteinase, while it was scarcely affected by diethylpyrocarbonate. The activity was also inhibited by DTNB and p-chloromercuribenzoate. Addition of hydrocarbon compounds such as ethylene glycol, glycerol, Triton X-100 and poly (ethylene glycol) to the reaction mixture was found to decrease the matrix proteinase activity. Neither cytochrome c nor glutamate dehydrogenase was hydrolyzed when subjected to the matrix proteinase activity in vitro. On the other hand, cytochrome c oxidase was effectively hydrolyzed, and the enzyme associated with the mitochondrial innermembrane fragments was partially hydrolyzed by the major matrix proteinase activity.
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PMID:An alkaline thiol proteinase in the liver mitochondria of bullfrog, Rana catesbeiana. 298 31

The subcellular distribution of 2-oxoglutarate:glyoxylate carboligase was investigated in a normal human liver, a liver from a patient with pyridoxine-resistant primary hyperoxaluria type I and rat livers subjected to various degrees and types of trauma. On continuous sucrose gradients most of the carboligase fractionated with a peak equilibrium density of 1.19-1.20 g/cm3 and paralleled the distribution of the major peaks of monoamine oxidase, glutamate dehydrogenase and cytochrome oxidase and can be considered to be mitochondrial. Various proportions of the carboligase and mitochondrial marker enzymes were found to be 'extramitochondrial' (at or near the top of the sucrose gradients), depending on the liver source and the severity of trauma to which they were subjected. Carboligase, monoamine oxidase (outer membrane marker) and glutamate dehydrogenase (matrix marker) were released from mitochondria by the homogenization and centrifugation procedures, to the extent of 19.9%, 32.4% and 11.5% respectively in hyperoxaluric liver, 12.5%, 17.9% and 8.2% in normal human liver and 3.0%, 4.9% and 3.8% in control rat liver. The proportion of extramitochondrial cytochrome oxidase (inner membrane marker) was virtually undetectable in both human and rat livers. However, sonication of rat liver homogenates or the addition of the detergent Triton X-100 caused a massive release of all four enzymes. The extramitochondrial carboligase was probably in the form of a free protein of very high molecular weight or aggregate, rather than associated with a mitochondrion-derived organelle. Subfractionation of a rat liver mitochondrial preparation indicated that most of the carboligase activity paralleled activities of 2-oxoglutarate decarboxylase, citrate synthase and glutamate dehydrogenase and was probably located in the matrix.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Mitochondrial damage and the subcellular distribution of 2-oxoglutarate:glyoxylate carboligase in normal human and rat liver and in the liver of a patient with primary hyperoxaluria type I. 300 79

The principally mitochondrial enzyme glutamate dehydrogenase (GDH) exhibited low-intensity, uniform immunoreactivity in neurons and intense heterogeneous labeling of glial cells of rat brain. Simultaneous peroxidase labeling for GDH and immunoautoradiography for glial fibrillary acidic protein (GFAP) confirmed the astrocytic localization of the enzyme. Immunoreactivity in astrocytes, but not in neurons, required the presence of Triton X-100 as a solubilizing agent. Most of the intensely labeled glial processes were localized to regions previously reported as containing moderate to high densities of binding sites for the excitatory amino acids, L-glutamate or L-aspartate, and glutamatergic fibers. These included several forebrain regions, such as the superficial layers of the rostral neocortex, dorsal neostriatum, nucleus accumbens, septohippocampal nucleus, intralaminar thalamic nuclei, and external capsules. However, the central gray of the midbrain, the nuclei of the reticular formation, brain stem regions projecting to the cerebellum, and cranial nuclei of the trigeminal and vagal nerves also exhibited intense glial labeling for GDH, even though some of these regions are known to receive only weak glutamatergic projections. A second factor determining the distribution of GDH appeared to be neuronal activity, as assessed by correspondence with reported high densities of cytochrome oxidase. We conclude that GDH enriched in glial populations exists in a subcellular compartment distinct from that of neurons and may serve as one of the enzymes involved in glutamatergic transmission. Deficiencies of glial GDH and the consequent cytotoxic effects of high levels of excitatory amino acids may contribute to a number of neurodegenerative disorders.
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PMID:Regional distribution of astrocytes with intense immunoreactivity for glutamate dehydrogenase in rat brain: implications for neuron-glia interactions in glutamate transmission. 330 25

Glutamate dehydrogenase (GDH, EC 1.4.1.2) has long been used as a marker for mitochondria in brain and other tissues, despite reports indicating that GDH is also present in nuclei of liver and dorsal root ganglia. To examine whether GDH can be used as a marker to differentiate between mitochondria and nuclei in the brain, we have measured GDH by enzymatic activity and on immunoblots in rat brain mitochondria and nuclei which were highly enriched by density-gradient centrifugation methods. The activity of GDH was enriched in the nuclear fraction as well as in the mitochondrial fraction, while the activities of other "mitochondrial" enzymes (fumarase, NAD-isocitrate dehydrogenase and pyruvate dehydrogenase complex) were enriched only in the mitochondrial fraction. Immunoblots using polyclonal antibodies against bovine liver GDH confirmed the presence of GDH in the rat brain nuclear and mitochondrial fractions. The GDH in these two subcellular fractions had a very similar molecular weight of 56,000 daltons. The mitochondrial and nuclear GDH differed, however, in their susceptibility to solubilization by detergents and salts. The mitochondrial GDH could be solubilized by extraction with low concentrations of detergents (0.1% Triton X-100 and 0.1% Lubrol PX), while the nuclear GDH could be solubilized only by elevated concentrations of detergents (0.3% each) plus KCl (greater than 150 mM). Our results indicate that GDH is present in both nuclei and mitochondria in rat brain. The notion that GDH may serve as a marker for mitochondria needs to be re-evaluated.
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PMID:The subcellular localization of glutamate dehydrogenase (GDH): is GDH a marker for mitochondria in brain? 352 73

Antigens were derived from hatched and activated oncospheres of Taenia pisiformis which had been separated from embryophoric debris by centrifugation on Percoll. Crude oncospheral antigen was prepared by freeze-thawing and sonication of oncospheres at 4 C, and a supernatant of crude antigen was collected following centrifugation at 100,000g. Other antigens tested were the supernatants collected after 100,000g centrifugation of crude antigen solubilized in Triton X-100, butanol, lithium diiodosalicylic acid, KCl, sodium dodecyl sulfate, or sodium deoxycholate. When groups of rabbits were immunized with the various antigens and challenged with T. pisiformis eggs, both sodium deoxycholate- and Triton X-100-solubilized antigens stimulated a level of protection similar to the crude antigen. All other antigens failed to stimulate significant protective immunity. When sodium deoxycholate-solubilized antigen was fractionated using high-performance liquid chromatography, the major host-protective components were in the fractions with molecular weight greater than 140,000. Levels of the enzyme, glutamate dehydrogenase (EC 1.4.1.2), in the serum of rabbits challenged with T. pisiformis eggs closely reflected the degree of liver damage caused by migrating larvae, and were not markedly elevated in those rabbits effectively immunized using the crude or sodium deoxycholate-solubilized antigens.
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PMID:Taenia pisiformis: protective immunization of rabbits with solubilized oncospheral antigens. 399 24

The carnitine acetyltransferase and glutamate dehydrogenase activities of guinea-pig liver and other tissues were estimated. Both enzymes are wholly mitochondrial, and can only be fully observed after disruption of the mitochondrion. Triton X-100 (0.1%) or freeze-drying revealed more activity than other methods tried. In mitochondria prepared and suspended in 0.25m-sucrose and in cell cytoplasm only small fractions of the total enzymic activity could be observed in guinea-pig liver: on average 7.5% of carnitine acetyltransferase and 5.5% of glutamate dehydrogenase. It is concluded that, in liver or mammary gland of goat, guinea pig or rat, little or no carnitine acetyltransferase is available in vivo to acetyl-CoA outside the mitochondrion.
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PMID:The availability of carnitine acetyltransferase in mitochondria from guinea-pig liver and other tissues. 570 22

The effect of phosphoenolpyruvate on glutamate dehydrogenase activity was studied in both intact and Triton X-100-treated rabbit renal mitochondria. The intramitochondrial phosphoenolpyruvate content was modulated by application of both 3-MPA, an inhibitor of phosphoenolpyruvate carboxykinase, and BTCA, which inhibits the tricarboxylate-transporting system. The data indicate that: (i) phosphoenolpyruvate is a potent inhibitor of glutamate dehydrogenase activity; and (ii) its inhibitory effect on the enzyme may be abolished by leucine and ADP, activators of glutamate dehydrogenase.
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PMID:Inhibition of glutamate dehydrogenase activity in rabbit renal mitochondria by phosphoenolpyruvate. 662 69


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