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

Fifteen enzymes participating in epidermal energy metabolism in zinc-deficient and -supplemented rats were assayed utilizing fluorometric microchemical techniques. In the zinc-deficient group, the activities of six enzymes catalyzing glycolysis decreased by 30 to 50% of the control; the most dramatic decreases were found in phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. Zinc deficiency caused a 31% decrease in the activity of glucose-6-phosphate dehydrogenase, a 63% decrease in fumarate hydratase, a 46% decrease in glutamate dehydrogenase, and a 30 to 40% decrease in aminotransferases.
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PMID:Enzyme activities in the epidermis of zinc-deficient rats. 17 16

A crude mitochondrial fraction (M) derived from manually disrupted cerebellar tissue and enriched in choline acetyltransferase (ChAT) activity was fractionated by centrifugation in discontinuous and continuous sucrose gradients. Further purification of 'cholinergic' synaptosomes was achieved (relative specific activity (RSA) of ChAT greater than 3), but the overlap with other synaptosomal populations was still considerable. Hand-homogenized cerebella processed through the full fractionation procedure described here and in previous papers yielded preparations enriched in certain neuronal structures and a fraction in which 'heavy' free mitochondria was concentrated. To characterize these preparations the activities of two transmitter enzymes (CHAT and glutamate decarboxylase, GAD) and 6 mitochondrial enzymes (succinate dehydrogenase (SDH), glutamate dehydrogenase (GDH), monoamine oxidase, citrate synthase, fumarase and GABA-aminotransferase) were determined. The distribution of the transmitter enzymes was clearly different in the preparations containing various neuronal structures. The GAD:ChAT RSA ratio was 2.4 for the glomerulus particles, 1.3 for the molecular layer fragments, 0.6 for the myelinated axon segments, and 0.2 for the 'cholinergic' synaptosomes. The mitochondrial enzyme profile of the preparations comprising mainly neuronal structures differed markedly from that of the 'free' mitochondrial fraction. Notably the latter was greatly enriched in GDH (RSA 5.6), whereas the SDH:GDH RSA ratio was relatively high in the former preparations. Nevertheless there were notable differences in the enzyme profile of the fractions of predominantly neuronal origin indicating that the enzyme composition of mitochondria of neuronal processes is not uniform.
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PMID:Subcellular fractionation of rat cerebellum: separation of synaptosomal populations and heterogeneity of mitochondria. 21 84

A strain of fibroblasts partially trisomic for the larger part of 1q (Norwood and Hoehn, 1974) contains about 1.5 times as much fumarate hydratase (FH) as various control-strains. This gene dosage effect was ascertained by (1) comparative measurements of the specific activity; (2) relating the specific activity of FH to that of reference enzymes, not influenced by the chromosomal anomaly; and (3) by immunoprecipitation methods, using a rabbit antiserum against pig heart FH which cross-reacts with the human enzyme. Among others, this gene dosage effect can be demonstrated numerically by the following parameters: Ratio of the average specific activity of FH in the trisomic strain to that of the control strains: 1.53. Corresponding ratio after dividing FH activity by that of reference enzymes; for acid phosphatase: 1.58, for glutamate dehydrogenase: 1.53. Average ratio of the immunoprecipitation areas obtained upon radial immunodiffusion according to Mancini et al. (1965): 1.56.
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PMID:Gene dosage effect for fumarate hydratase (FH; E.C. 4.2.1.2) in partial trisomy 1. 31 55

The mitochondrial matrix subfractions from rat liver, kidney cortex, brain, heart, and skeletal muscle were isolated and their protein components were resolved by two-dimensional polyacrylamide gel electrophoresis, revealing between 120 and 150 components for each matrix subfraction. Excellent resolution was obtained utilizing a pH 5 to 8 gradient in the first dimension and in 8 to 13% exponential acrylamide gradient in the second dimension, increasing the number of mitochondrial matrix proteins observed 3-fold over one-dimensional systems. Protein components tentatively identified by co-migration with pure enzymes and by known tissue distributions are carbamoyl-phosphate synthetase (EC 2.7.2.5), ornithine transcarbamylase (EC 2.1.3.3), glutamate dehydrogenase (EC 1.4.1.3), pyruvate carboxylase (EC 6.4.1.1), citrate synthase (EC 4.1.3.7), fumarase (EC 4.2.1.2), aconitase (EC 4.2.1.3), alpha-ketoglutarate dehydrogenase (EC 1.2.4.2), dihydrolipoyl transsuccinylase (EC 2.3.1.12), lipoamide dehydrogenase (EC 1.6.4.3), glutamate-aspartate aminotransferase (EC 2.6.1.1), and the two subunits of pyruvate dehydrogenase (EC 1.2.4.1). Protein components unambiguously identified by peptide mapping are citrate synthase, aconitase, and pyruvate carboxylase. The inner membrane subfraction from rat liver mitochondria was also resolved two dimensionally; the alpha and beta subunits of ATPase (F1) (EC 3.6.1.3) were identified by peptide mapping.
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PMID:Resolution of rat mitochondrial matrix proteins by two-dimensional polyacrylamide gel electrophoresis. 44 63

The level of aspartate aminotransferase in liver mitochondria was found to be approximately 140 microM, or 2-3 orders of magnitude higher than its dissociation constant in complexes with the inner mitochondrial membrane and the high molecular weight enzymes (M(r) = 1.6 x 10(5) to 2.7 x 10(6)) carbamyl-phosphate synthase I, glutamate dehydrogenase, and the alpha-ketoglutarate dehydrogenase complex. The total concentration of aminotransferase-binding sites on these structures in liver mitochondria was more than sufficient to accommodate all of the aminotransferase. Therefore, in liver mitochondria, the aminotransferase could be associated with the inner mitochondrial membrane and/or these high molecular weight enzymes. The aminotransferase in these hetero-enzyme complexes could be supplied with oxalacetate because binding of aminotransferase to the high molecular weight enzymes can enhance binding of malate dehydrogenase, and binding of both malate dehydrogenase and the aminotransferase facilitated binding of fumarase. The level of malate dehydrogenase was found to be so high (140 microM) in liver mitochondria, compared with that of citrate synthase (25 microM) and the pyruvate dehydrogenase complex (0.3 microM), that there would also be a sufficient supply of oxalacetate to citrate synthase-pyruvate dehydrogenase.
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PMID:Glutamate-malate metabolism in liver mitochondria. A model constructed on the basis of mitochondrial levels of enzymes, specificity, dissociation constants, and stoichiometry of hetero-enzyme complexes. 135 Feb 79

The ubiquinone systems and electrophoretic comparison of enzymes were used to determine the relatedness among 64 isolates of seven Aspergillus spp. These were 31 clinical and 3 nonclinical isolates of Aspergillus fumigatus Fres., 2 isolates of A. nidulellus Samson & W. Gams, 8 isolates of A. terreus Thom, 4 isolates of A. flavus Link, 1 isolate of A. oryzae (Ahlburg) Cohn, 14 isolates of A. niger van Tieghem, and 1 isolate of A. japonicus Saito. The enzymes glucose 6-phosphate dehydrogenase, lactate dehydrogenase, glutamate dehydrogenase, fumarase, and malate dehydrogenase were examined. The relative mobilities were analyzed numerically. The results were presented as a dendrogram. Isolates from clinical and nonclinical sources within the same species had identical ubiquinone systems and identical or very similar enzyme patterns. In the dendrogram, 64 of the tested isolates were separated into seven major clusters at a 60% similarity level. Each major cluster corresponds to a single species. On the dendrogram, A. fumigatus isolates showed homogeneity, whereas A. niger isolates showed relative heterogeneity; in particular, A. niger MF-24 and the other A. niger isolates were distantly linked to each other. All A. fumigatus isolates had the Q-10 ubiquinone system and formed a single major cluster at a similarity level of 73% or greater. Glucose 6-phosphate dehydrogenase and glutamate dehydrogenase were key enzymes for differentiating all clinical and nonclinical isolates of A. fumigatus from the other Aspergillus spp. Ubiquinone systems and enzyme patterns appear to be objective and useful indicators for use in the precise identification of clinical isolates of Aspergillus spp.
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PMID:Application of ubiquinone systems and electrophoretic comparison of enzymes to identification of clinical isolates of Aspergillus fumigatus and several other species of Aspergillus. 150 May 6

The activity of 7 mitochondrial enzymes, fumarase, NAD-malate dehydrogenase (MDH), citrate synthase (CS), valine dehydrogenase (VDH), succinate dehydrogenase (SDH), glutamate dehydrogenase (GDH), pyruvate dehydrogenase complex (PDHC) has been measured in platelet preparations from patients affected by Friedreich's ataxia (FA), dominant and non-dominant olivopontocerebellar atrophy (DOPCA, NDOPCA) and normal individuals. Significant decreases of GDH (P less than 0.01), PDHC (P less than 0.01), VDH (P less than 0.05) and SDH (P less than 0.05) activities were observed in FA patients. Significant decreases of GDH (P less than 0.01), PDHC (P less than 0.01), VDH (P less than 0.05), SDH (P less than 0.05) and CS (P less than 0.05) activities were Observed in ND-OPCA patients, whereas in DOPCA patients only GDH activity was significantly (P less than 0.05) decreased. In 8 of 10 patients with FA and in all patients with NDOPCA the activity of one or more of 4 enzymes, i.e. GDH, VDH, SDH, PDHC, was lower than the lowest of control values. Four of 6 patients with DOPCA had GDH activity lower than the lowest of control values. These results indicate that abnormalities of mitochondrial metabolism is a constant element in hereditary ataxia and suggest that the alteration primary leading to the different types of ataxias should be related to mitochondrial oxidative metabolism, at least at a regulatory level.
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PMID:Abnormalities of mitochondrial enzymes in hereditary ataxias. 281 70

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

The mitochondrial inner membrane lost its selectivity for the transport of solutes after reaction of hydrophobic sulfhydryl groups with alkylating agents (maleimide derivatives). The nature of the thiol reagent-induced membrane perturbations was investigated. Modifications of the interactions between membrane components after treatment with thiol reagents were assessed by measuring the binding parameters of 1-anilinonaphtalene-8-sulfonate. An enhancement (about 50%) of the fluorescence intensity, a weak increase of the number of binding sites, and a decrease of the apparent dissociation constant were observed. However, no significant modification of the net surface charge was detected. The osmotic behavior of mitochondria in hypotonic solutions of sucrose was altered after thiol modification. The outer membrane did not seem to influence the matricial volume expansion when thiols were alkylated. After swelling in an isotonic solution of permeant ions, N-butylmaleimide-treated mitochondrial lost one-half of their malate dehydrogenase content, whereas fumarase and glutamate dehydrogenase did not leave the matrix space. Addition of polyethylene glycol of molecular weight below 6000 to swollen mitochondria induced a rapid but transient shrinkage. In swollen mitochondria, the above results indicate a possible holes formation in the membrane structure. The size of these holes was estimated to be about 3 nm. This process which required the presence of the outer membrane, was favored by increasing the temperature and was antagonized by specific effectors of the adenine nucleotide translocator.
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PMID:Crucial role of sulfhydryl groups in the mitochondrial inner membrane structure. 399 77

Octanoic acid inhibits, in vitro, the bacterial enzymes glucose-6-phosphate dehydrogenase, phosphofructokinase, pyruvate kinase, fumarase, lactate dehydrogenase, and the malic enzyme of Arthrobacter crystallopoietes. The free fatty acid appears to act as an inhibitor of lipogenesis, although it does not affect the rate of gluconeogenesis. To demonstrate that this inhibition may be of physiological significance in vivo, those enzymes not involved in lipogenesis, such as fructose-1, 6-diphosphatase, phosphoglucomutase, phosphohexoisomerase, aconitase, nicotinamide adenine dinucleotide phosphate (NADP) isocitrate dehydrogenase, NADP glutamate dehydrogenase, malate dehydrogenase, and isocitrate lyase, were assayed and found not to be inhibited by the free fatty acid.
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PMID:Selective inhibition of bacterial enzymes by free fatty acids. 430 71


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