Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 specific activities of D-3-hydroxybutyrate dehydrogenase (BDH) and glutamate dehydrogenase (GDH) are reduced in the liver and kidney of rats intoxicated with 2.5 mg Cd/kg body wt and sacrificed after 24 h; conversely ketone-body concentration is strongly increased in both of these organs and blood. In the same animals a great stimulation of antioxidant enzymes glutathione reductase and glutathione peroxidase occurs. The prooxidant state induced by cadmium in liver mitochondria and microsomes is unaffected by superoxide dismutase, catalase, or mannitol, whereas it is completely blocked by vitamin E thus excluding the involvement of reactive oxygen species in this process. The mechanism by which cadmium induces lipid peroxidation has been investigated by measuring the effect of this metal on liposomes. Ninety-minute treatment of liposomes with CdCl2 does not induce any lipid peroxidation. In contrast, Fe2+ ions under the same conditions cause strong liposome peroxidation. It has also been observed that cadmium promotes a time-dependent iron release from biological membranes. When lipid peroxidation is induced by a low concentration (5 microM) of FeCl2, in place of CdCl2, the characteristics of this process and the sensitivity to the various antioxidants used are similar to those observed with Cd. From these results we conclude that the prooxidative effect of cadmium is an indirect one since it is mediated by iron. With regard to the inhibitory effect on BDH and GDH following cadmium intoxication, it does not appear to be imputable to lipid peroxidation since in vitro investigations indicate that the presence of vitamin E does not remove the inhibition at all.
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PMID:Enzyme activity alteration by cadmium administration to rats: the possibility of iron involvement in lipid peroxidation. 934 63

The physiological features of the mildiomycin production by Streptoverticillium rimofaciens were examined in iron-sufficient and -deficient media. Activities of NADP-linked glutamate dehydrogenase (GDH) and aspartate aminotransferase (AAT) were markedly enhanced by the addition of 10 micrograms/ml of ferrous ion into culture. Ammonium nitrogen assimilation increased with the increase in mildiomycin production. These indicate that ferrous ion contributes the supply of amino acids as a precursor of mildiomycin production. In the iron-sufficient medium, glutamate, aspartate, serine and arginine in cells were 2 to 10-fold to those in the iron-deficient medium. The major amino acid excreted from cells was arginine in the iron-sufficient culture, while in the iron-deficient culture, valine. Change in the amino acid profile by addition of ferrous ion was useful for mildiomycin biosynthesis, in which ferrous ion played a leading role in amino acid metabolism.
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PMID:Effect of ferrous ion on amino acid metabolism in mildiomycin production by Streptoverticillium rimofaciens 943 91

Severe iron deficiency results in complex systemic disorders e.g., including metabolism of energy and minerals. To investigate whether also moderate iron depletion may alter the activities of citric cycle enzymes and the cytochrome oxidase, the trace element status, and serum enzymes indicative of cell damage, this experiment was carried out with rats supplied with sub-optimal iron (9, 13 and 18 mg iron per kg diet) over a total of 5 weeks. The study included 3 pair-fed groups and an ad libitum group, fed with 50 mg iron/kg diet. All iron-restricted rats were classified as iron-deficient on the basis of reduced iron concentrations in body and iron-depending blood parameters. Body weight gain and catalase activity in kidney were lowered in rats receiving the lowest dietary iron level, exclusively. Rats fed 9 and 13 mg iron per kg diet had nearly 6- and 3-fold, respectively higher platelet counts in blood than their corresponding pair-fed controls. The activities of transaminases ASAT and ALAT, alkaline phosphatase, glutamate dehydrogenase and lactate dehydrogenase in serum which are indicative of cell damage were also markedly influenced by moderate dietary iron restriction, in which the enzyme levels in serum increased with intensifying iron depletion. Although, moderate iron restriction to young male rats was associated with marked alterations in iron status and serum enzymes, the activities of tricarboxylic acid cycle enzymes including malic dehydrogenase, fumarase, and isocitric dehydrogenase as well as cytochrome oxidase in liver remained largely unaffected. Only hepatic aconitase showed a somewhat reduction with iron depletion. Moreover, iron restriction was also accompanied with an accumulation of copper in liver which was significant for rats fed 9 and 13 mg iron per kg diet, whereas zinc status remained completely unaffected by moderate iron deficiency. It can be concluded, that a short-term moderate iron deficiency with ranging hemoglobin concentrations from 66 and 121 g/L, was accompanied with altered platelet counts, serum enzyme activities indicative of cell damage, and hepatic copper concentrations, but the activities of the tricarboxylic acid cycle enzymes and cytochrome oxidase in liver remained largely unaffected.
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PMID:Effect of different degrees of moderate iron deficiency on the activities of tricarboxylic acid cycle enzymes, and the cytochrome oxidase, and the iron, copper, and zinc concentrations in rat tissues. 980 Mar 17

Anoxic, fresh-water enrichment cultures to oxidize different organosulfonates were set up with nitrate, ferric iron or sulfate as electron acceptors. Pure cultures were easily obtained with two naturally occurring sulfonates, cysteate (2-amino-3-sulfopropionate) and taurine (2-aminoethanesulfonate), under nitrate-reducing conditions. These two sulfonates were also oxidized during reduction of iron(III), though isolation of pure cultures was not successful. One nitrate-reducing cysteate-oxidizing bacterium, strain NKNCYSA, was studied in detail. It was identified as Paracoccus pantotrophus. Eighteen sulfonates were tested, and the organism degraded cysteate, taurine, isethionate (2-hydroxyethanesulfonate), sulfoacetate or 3-aminopropanesulfonate with concomitant reduction of nitrate, presumably to molecular nitrogen. The carbon skeleton of these substrates was converted to cell material and, presumably, CO2. The amino group was released as ammonia and the sulfono moiety was recovered as sulfate. Cell-free extracts of P. pantotrophus NKNCYSA contained constitutive L-cysteate:2-oxoglutarate aminotransferase (EC 2.6.1.-) and glutamate dehydrogenase (EC 1.4.1.4). Taurine:pyruvate aminotransferase, in contrast, was inducible.
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PMID:Anaerobic oxidations of cysteate: degradation via L-cysteate:2-oxoglutarate aminotransferase in Paracoccus pantotrophus. 1037 31

Abnormalities in energy metabolism and oxidative stress accompany many neurodegenerative diseases, including progressive supranuclear palsy (PSP). Previously, we showed decreased activities of a mitochondrial enzyme complex, alpha-ketoglutarate dehydrogenase complex (KGDHC), and marked increases in tissue malondialdehyde levels in post-mortem superior frontal cortex from the patients with PSP. The current study demonstrates that KGDHC is also significantly diminished (-58%) in the cerebellum from patients with PSP (n = 14), compared to age-matched control brains (n = 13). In contrast to cortex, markers of oxidative stress, such as malondialdehyde, tyrosine nitration or general protein carbonyl modification, did not increase in cerebellum. Furthermore, the protein levels of the individual components of KGDHC did not decline. The activities of two other mitochondrial enzymes were measured to determine whether the changes in KGDHC were selective. The activity of aconitase, a mitochondrial enzyme with an iron/sulfur cluster, is also significantly diminished (-50%), whereas glutamate dehydrogenase activity is unchanged. The present results suggest that the interaction of metabolic impairment and oxidative stress is region-specific in PSP brain. In cerebellum, reductions in KGDHC occur in the absence of increases in common measures of oxidative stress, and may underlie the metabolic deficits and contribute to pathological and clinical manifestation related to the cerebellum in patients with PSP.
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PMID:Mitochondrial impairment in the cerebellum of the patients with progressive supranuclear palsy. 1174 33

Birds have evolved alternate physiologic strategies to contend with dehydration, starvation, malnutrition, and reproduction. Basic anatomic and functional differences between birds and mammals impact clinical chemistry values and their evaluation. Interpretation of the results of standard biochemical analyses, including BUN, alanine aminotransferase, aspartate aminotransferase, creatine kinase, gamma glutamyltransferase, bilirubin, ammonia, alkaline phosphatase, cholesterol, bile acids, glucose, albumin, globulins, calcium, phosphorus, prealbumin (transthyretin), fibrinogen, iron, and ferritin, is reviewed and discussed in relation to these physiological differences. The use and interpretation of alternative analytes appropriate for avian species, such as uric acid, biliverdin, glutamate dehydrogenase, and galactose clearance, also are reviewed. Normal avian urine and appropriate use of urinalysis, an integral part of laboratory diagnosis in mammalian species that frequently is omitted from avian diagnostic protocols, is discussed.
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PMID:Clinical chemistry of companion avian species: a review. 1218 2

In isolated tubular segments (ITS) of rat kidney cortex, we studied the effect of hemoglobin (Hb) on reoxygenation damage. All tubules were suspended in Ringer's solution containing 5-mm glycine and oxygenated for 30 min with 95% O(2):5% CO(2), followed by a 30-min period with 95% N(2):5% CO(2), and final reoxygenation for 60 min. Untreated tubules served as controls. Different concentrations of free Hb and equivalent amounts of intact erythrocytes were added to the incubation medium. Secondly, we added deferoxamine (DFO) to Hb and erythrocytes. Membrane leakage and lipid peroxidation were measured by lactate dehydrogenase and glutamate dehydrogenase and the development of thiobarbituric acid reactive substances. Cell function was quantified by gluconeogenesis and intracellular potassium accumulation. Hb exerted concentration-dependent cytotoxic effects indicated by significantly increased enzyme leakage rates, lipid peroxidation and a significantly decreased cell function (P < 0.05), in ITS during hypoxia, and subsequent reoxygenation. Moreover, we found that toxicity of both Fe(2+) and Fe(3+) ions increased with rising concentration. However, Fe(2+) showed a higher tissue toxicity than Fe(3+). DFO reduced significantly the reoxygenation damage of free Hb and iron ions. Our data clearly demonstrate a pronounced cytotoxic effect of free Hb in ITS, which critically depended on the reduction state of the iron ions.
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PMID:Hemoglobin induces cytotoxic damage of glycine-preserved renal tubules. 1785 46

The first proteomic analysis of Trypanosoma cruzi resistance to Benznidazole (BZ) is presented. The differential proteome of T. cruzi with selected in vivo resistance to Benznidazole (BZR and Clone27R), its susceptible pairs (BZS and Clone9S), and a pair from a population with Benznidazole- in vitro-induced resistance (17LER) and the susceptible pair 17WTS were analyzed by two-dimensional gel electrophoresis (2-DE) followed by mass spectrometry (MS) for protein identification. Out of 137 spots analyzed through MS, 110 were identified as 56 distinct proteins. Out of the 56 distinct proteins, 36 were present in resistant, 9 in susceptible, and 11 in both phenotypes. Among the proteins identified in resistant samples, 5 were found in Cl 27R and in BZR (calpain-like cysteine peptidase, hypothetical protein conserved 26 kDa, putative peptidase, peroxiredoxin and tyrosine amino transferase) and 4 in Cl 27R and 17LER (cyclophilin A, glutamate dehydrogenase, iron superoxide dismutase and nucleoside diphosphate kinase). As for the proteins identified in Benznidazole-susceptible samples, PGF-2a was found in BZS and 17WTS. A functional category analysis showed that the proteins involved with transcription and protein destination were overexpressed for the Benznidazole-resistant phenotype. Thus, the present study provides large-scale, protein-related information for investigation of the mechanism of T. cruzi resistance to Benznidazole.
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PMID:Proteomic analysis of Trypanosoma cruzi resistance to Benznidazole. 1843 57

The fission yeast Schizosaccharomyces pombe excretes and accumulates the hydroxamate-type siderophore ferrichrome. The sib1(+) and sib2(+) genes encode, respectively, a siderophore synthetase and an l-ornithine N(5)-oxygenase that participate in ferrichrome biosynthesis. In the present report, we demonstrate that sib1(+) and sib2(+) are repressed by the GATA-type transcriptional repressor Fep1 in response to high levels of iron. We further found that the loss of Fep1 results in increased ferrichrome production. We showed that a sib1Delta sib2Delta mutant strain exhibits a severe growth defect on iron-poor media. We determined that two metabolic pathways are involved in biosynthesis of ornithine, an obligatory precursor of ferrichrome. Ornithine is produced by hydrolysis of arginine by the Car1 and Car3 proteins. Although car3(+) was constitutively expressed, car1(+) transcription levels were repressed upon exposure to iron, with a concomitant decrease of Car1 arginase activity. Ornithine is also generated by transformation of glutamate, which itself is produced by two separate biosynthetic pathways which are transcriptionally regulated by iron in an opposite fashion. In one pathway, the glutamate dehydrogenase Gdh1, which produces glutamate from 2-ketoglutarate, was repressed under iron-replete conditions in a Fep1-dependent manner. The other pathway involves two coupled enzymes, glutamine synthetase Gln1 and Fe-S cluster-containing glutamate synthase Glt1, which were both repressed under iron-limiting conditions but were expressed under iron-replete conditions. Collectively, these results indicate that under conditions of iron deprivation, yeast remodels metabolic pathways linked to ferrichrome synthesis in order to limit iron utilization without compromising siderophore production and its ability to sequester iron from the environment.
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PMID:Iron-dependent remodeling of fungal metabolic pathways associated with ferrichrome biosynthesis. 2043 71

To evaluate the health and nutritional status of 3 wild Australian psittacine species, plasma and hepatic mineral concentrations and plasma biochemical values were measured in wild-caught galahs (Eolophus roseicapilla), long-billed corellas (Cacatua tenuirostris), and sulphur-crested cockatoos (Cacatua galerita). No correlations were found between hepatic and plasma mineral levels. Mean plasma calcium (1.79 mmol/L [7.16 mg/dL]) and sodium (103 mmol/ L [103 mEq/L]) concentrations were lower, whereas mean total phosphorus (6.53 mmol/L [20.22 mg/dL]) and potassium (8.87 mmol/L [8.87 mEq/L]) concentrations were higher than values for captive counterparts. Plasma iron levels were higher than those reported for captive counterparts, with evidence of interspecific (sulphur-crested cockatoos, 109 micromol/L [609 microg/dL]; corellas, 57 micromol/L [318 microg/dL]; galahs, 90 micromol/L [503 microg/dL]) and temporal variation (galahs: May, 107 micromol/L [598 microg/dL]; July, 59 micromol/L [330 microg/dL]). Hepatic iron concentrations were as high as 1030 mg/kg. Interspecific variation was minimal in mean plasma selenium (11.8 micromol/L [929 microg/L]) and zinc (31.2 micromol/L [204 microg/dL]) concentrations. Plasma biochemical values varied significantly from reported reference ranges. Ranges for total protein, albumin, and bile acid concentrations were lower, whereas uric acid, glutamate dehydrogenase, amylase, and cholesterol concentrations were higher than those previously reported for these species, and interspecific variation was evident. Variation in measures of mineral status or plasma biochemical values between males and females were negligible. An evaluation of fecal microflora showed a distinct absence of gram-negative bacteria or budding yeast. Results of this study show that analyte values used to determine health and nutritional status of wild birds differ from those published for captive counterparts. Although analyte values appear to vary minimally by sex, distinct taxonomic and some temporal differences exist in values from wild birds of these 3 species.
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PMID:Health and nutritional status of wild Australian psittacine birds: an evaluation of plasma and hepatic mineral levels, plasma biochemical values, and fecal microflora. 2130 59


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