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)

Various flavins, FMN, FAD, and acriflavin, were immobilized to Sepharose using several different coupling methods. The only product stable enough to permit extended studies was acriflavin coupled to epoxy-substituted Sepharose. The nonenzymic oxidizing capacity towards NAD(P) H was investigated and a 25% specific activity, compared to that of free acriflavin, was observed. The reduced acriflavin was immediately auto-reoxidized in air and could thus be reused. It was shown that acriflavin-Sepharose preparations function as NAD(P)H oxidizing agents in a number of different dehydrogenase systems including lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH), malate dehydrogenase (MDH), alanine dehydrogenase (alaDH), and glutamate dehydrogenase (GDH). The amount of expensive coenzyme necessary for high product formation of such systems was thereby markedly reduced.
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PMID:Continuous regeneration of NAD(P)+ by flavins covalently bound to sepharose. 0 69

Glutamine synthetase (EC 6.3.1.2) was localized within the matrix compartment of avian liver mitochondria. The submitochondrial localization of this enzyme was determined by the digitonin-Lubrol method of Schnaitman and Greenawalt (35). The matrix fraction contained over 74% of the glutamine synthetase activity and the major proportion of the matirx marker enzymes, malate dehydrogenase (71%), NADP-dependent isocitrate dehydrogenase (83%), and glutamate dehydrogenase (57%). The highest specific activities of these enzymes were also found in the matrix compartment. Oxidation of glutamine by avian liver mitochondria was substantially less than that of glutamate. Bromofuroate, an inhibitor of glutamate dehydrogenase, blocked oxidation of glutamate and of glutamine whereas aminoxyacetate, a transaminase inhibitor, had little or no effect with either substrate. These results indicate that glutamine metabolism is probably initiated by the conversion of glutamine to glutamate rather than to an alpha-keto acid. The localization of a glutaminase activity within avian liver mitochondria plus the absence of an active mitochondrial glutamine transaminase is consistent with the differential effects of the transaminase and glutamate dehydrogenase inhibitors. The high glutamine synthetase activity (40:1) suggests that mitochondrial catabolism of glutamine is minimal, freeing most of the glutamine synthesized for purine (uric acid) biosynthesis.
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PMID:Submitochondrial localization and function of enzymes of glutamine metabolism in avian liver. 1 18

Activities of 9 enzymes were determined biochemically in the endometrium. In Trial I (five women) 25 mg progesterone were injected i.m. on day 9 of the cycle; and endometrial biopsy taken 24 hours later was compared with endometrium from day 10 and day 21, taken in two untreated cycles from the same volunteers. Similarly, in Trial II (five women) 50 mg progesterone were injected on day 9, biopsy taken on day 11 and compared with days 11 and 21 from untreated cycles. The specific activites of lactate dehydrogenase, isocitrate dehydrogenase (ICDH), malate dehydrogenase, glutamate dehydrogenase, beta-glucuronidase, acid phosphatase (ACP) and alkaline phosphatase (AP) were significantly higher in the secretory phase. Twenty-five milligrams progesterone (after 24 hours) caused increases of some enzymes, significant only for AP. Fifty milligrams (after 48 hours) increased significantly the activity of ICDH and ACP. Biochemical changes, especially increase of ICDH, can be used for detection of the effect of progesterone on the endometrium.
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PMID:Effect of endogenous and exogenous progesterone on human endometrial enzymes. 3 Jul 6

1) A lysosomal protease, a new cathepsin that inactivates glucose-6-phosphate dehydrogenase [EC 1.1.1.49] and some other enzymes and differs from cathepsin B [EC 3.4.22.1] was purified about 2,200-fold from crude extracts of rat liver by cell-fractionation, freezing and thawing, acetone treatment, gel filtration, and DEAE Sephadex and CM-Sephadex column chromatographies. 2) The new cathepsin was markedly activated by the thiol-reagent, 2-mercaptoethanol and inhibited by monoiodoacetate. 3) The molecular weight of the new cathepsin was found by Sephadex G-75 column chromatography to be 22,000, which is smaller than that of cathepsin B. 4) The optimum pH of the enzyme for inactivation of glucose-6-phosphate dehydrogenase was pH 5.0--5.5. The enzyme was unstable in alkali and on heat treatment. 5) The rates of inactivation of glucose-6-phosphate dehydrogenase, apo-ornithine aminotransferase [EC 2.6.1.13], apo-tyrosine aminotransferase [EC 2.6.1.5], apo-cystathionase [EC 4.4.1.1], glucokinase [EC 2.7.1.2], glyceraldehyde-3-phosphate dehydrogenase [EC 1.2.1.12], and malate dehydrogenase [EC 1.1.1.37] by the new cathepsin were higher than those by cathepsin B. However aldolase [EC 4.1.2.13] was inactivated more rapidly by cathepsin B than by the new cathepsin. Lactate dehydrogenase [EC 1.1.1.27], glutamate dehydrogenase [EC 1.4.1.2] and alcohol dehydrogenase [EC 1.1.1.1] were not inactivated by either cathepsin. Unlike cathepsin B, the new cathepsin scarcely hydrolyzes N-substituted derivatives of arginine.
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PMID:Purification and properties of a new cathepsin from rat liver. 3 59

Tetrahymena pyriformis Wh 14 was grown in Erlenmeyer flasks under continuous stirring at 30 degrees C for three days . After the culture had produced dry matter of about 100 mg HCB was added in acetone at a dose level of 0, 0.001, 0.1 and 1.0 ppm to the culture and incubated for another 7 days. At a dose level of 0.001 ppm the activity of delta-aminolevulinate dehydratase, hexokinase, and pyruvate kinase remained unaffected but was increased for glutamic-oxaloacetic transaminase, glutamic dehydrogenase, isocitrate dehydrogenase, and malate dehydrogenase while 0.1 ppm HCB increased the activity of all enzymes studied, the only exception being glutamic-pyruvic transaminase, the activity of which was depressed by HCB exposure. A concentration of 1.0 ppm HCB depressed the activity of most of the enzymes below control values with the exception of the two mitochondrial enzymes, MDH and ICDH, studied here.
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PMID:Effect of hexachlorobenzene (HCB) on the activity of some enzymes from Tetrahymena pyriformis. 10 53

Posthepatectomy coma was produced in 13 dogs and the cerebrums were biopsied for analysis of concentrations of glucose, glucose-6-phosphate, dihydroxyacetone-phosphate, phosphoenolpyruvate, pyruvate, lactate, citrate, alpha-ketogulutarate, fumarate, malate, oxaloacetate, adenosinetriphosphate, ammonia, and glutamine as well as for activities of glucokinase, phosphofructokinase, pyruvate kinase, isocitrate dehydrogenase, glutamate dehydrogenase, malate dehydrogenase, and malic enzyme. There were no differences from normal in the brain glycolytic substrate concentrations. Four of the Krebs cycle substrates were significantly reduced, but not differently than in dogs sedated for 24 hours. The glycolytic pathway, Krebs cycle, and related enzyme activities were not significantly altered. Cerebral adenosine triphosphate concentration was unchanged but the concentrations of ammonia and glutamine increased threefold.
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PMID:Effect of total hepatectomy on selected cerebral substrates and enzymes of the glycolytic pathways and Krebs cycle. 17 Jun 98

Two experiments were performed to examine the effects of intramuscular estradiol administration on the hepatic specific activities of some enzymes of lipid, carbohydrate and amino acid metabolism in the immature fowl. Estradiol increased the specific activities of the hepatic lipogenic enzymes, ATP citrate lyase and malate dehydrogenase (decarboxylating) (NADP), but had no effects on the activities of the glycolytic, gluconeogenic and amino acid metabolising enzymes except for pyruvate kinase and glutamate dehydrogenase which were reduced in activity in both experiments. The results indicate that the estrogen-induced increase in hepatic lipid biosynthesis is due to a specific effect on lipid metabolism and not to a general increase in liver metabolism.
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PMID:The effects of estradiol administration of the hepatic activities of some enzymes of carbohydrate, amino acid and lipid metabolism in the immature pullet. 18 3

Oxidoreductases were studied histochemically in 162 cases of neuroectodermal tumors. In order of decreasing activity in the cytoplasma these enzymes could be arranged as follows: NADH diaphorase, lactate dehydrogenase, NADPH diaphorase, glutamate dehydrogenase, glucose-6-phosphate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase, malate dehydrogenase. The weak activity of Krebs cycle enzymes and the relatively strong activity of other oxidoreductases, particularly of lactate dehydrogenase, permits to conclude that glycolysis prevails over oxidative processes in neuroectodermal tumor cells. But this should not be interpreted as a decrease of the Krebs cycle enzymes in astrocytoma and oligodendroglioma cells as compared with their parent cells because the latter themselves display a weak activity of these enzymes. A real decrease of Krebs cycle enzyme activity was established only for tumors, the parent cells of which are characterized by a strong (in choroid-papillomas) or moderate (in ependymomas) activity of these enzymes. Many neuroectodermal tumors, in particular those of astrocytic origin, demonstrate a certain correlation between the amount of cytoplasm and oxidoreductase activity. This results in enzymatic polymorphism of the tumor tissue. A certain similarity was established of the oxidoreductase activity in tumor cells and in reactive hypertophic astrocytes. This indicates that both tumor cells and reactive astrocytes may in certain conditions utilize similar mechanisms of increased metabolism. The oxidoreductase activity correlates not with the grade of anaplasia but with different directions of anaplasia reflected in different variants of neuroectodermal tumors. The concept "anaplasia" includes not only certain degrees of dedifferentiation of tumor cells but, as it has been shown histochemically, also an increase of metabolic processes in the tumor cell cytoplasma.
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PMID:Histochemistry of oxidoreductases, enzymatic polymorphism and anaplasia of neuroectodermal tumors. 18 68

The levels of several enzymes have been studied during sporulation of Saccharomyces cerevisia. The specific activities of ribonuclease and aminopeptidase I raised several-fold after transfer of the cells to sporulation medium, whereas the specific activities of phosphofructokinase, glucose-6-phosphate dehydrogenase, tryptophan synthase and pyruvate decarboxylase were not significantly altered. The specific activities of NAD-dependent glutamate dehydrogenase, isocitrate lyase, malate dehydrogenase and fructose bisphosphatase all decreased from the onset of sporulation. The inactivation of these latter enzymes was inhibited by cycloheximide and by inhibitors of energy metabolism. Hexokinase, alcohol dehydrogenase and glutamate oxaloacetate transaminase were partially lost from the cells during the period of ascus maturation. None of the enzyme changes observed proved to be 'sporulation-specific' in that it occurred exclusively in sporulating diploid yeast cells. Therefore it is postulated that the meiotic events and the metabolic changes required for ascospore formation are under separate genetic control in this organism. During sporulation, the cellular content of cytochromes b, c, and aa3 was reduced to 20% or less of that present in vegetative derepressed cells. Since the relative percentage of total to cycloheximide-insensitive mitochondrial protein synthesis was not significantly altered throughout sporulation, and the pattern of mitochondrially synthesized polypeptides was rather similar both in vegetative and in sporulating cells, it appeared that not only degradation but also synthesis and therefore turnover of the mitochondrially coded polypeptides of cytochromes b and aa3 took place during sporulation. The activity ratio of cytochrome c oxidase to F1-ATPase in submitochondrial particles isolated from vegetative cells and from purified asci was almost identical. This indicates that the loss of membrane-bound mitochondrial cytochromes during sporulation is probably due to a nonselective degradation of inner mitochondrial membrane proteins.
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PMID:Protein degradation during yeast sporulation. Enzyme and cytochrome patterns. 18 44

The changes induced by phenobarbital in cerebral enzymatic activities of the Krebs' cycle (citrate synthase, malate dehydrogenase) and electron transfer chain (total NADH-cytochrome c reductase and cytochrome oxidase) were studied. In addition, the activity of lactate dehydrogenase of acetylcholine esterase and of glutamate dehydrogenase was also studied. These enzymatic activities were evaluated in the homogenate in toto and in a crude mitochondrial fraction from rat brain. The modifications in some of these activities indicate that several new metabolic situations occur in brain tissue after phenobarbital treatment.
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PMID:Effect of phenobarbital on cerebral energy state and metabolism. Enzymatic activities. 23 Jun 18


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