Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q8NEX9 (reductase)
 26,410 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Subcellular localization of enzymes of arginine metabolism in Saccharomyces cerevisiae was studied by partial fractionation and stepwise homogenization of spheroplast lysates. These enzymes could clearly be divided into two groups. The first group comprised the five enzymes of the acetylated compound cycle, i.e., acetylglutamate synthase, acetylglutamate kinase, acetylglutamyl-phosphate reductase, acetylornithine aminotransferase, and acetylornithine-glutamate acetyltransferase. These enzymes were exclusively particulate. Comparison with citrate synthase and cytochrome oxidase, and results from isopycnic gradient analysis, suggested that these enzymes were associated with the mitochondria. By contrast, enzymatic activities going from ornithine to arginine, i.e., arginine pathway-specific carbamoylphosphate synthetase, ornithine carbamoyltransferase, argininosuccinate synthetase, and argininosuccinate lyase, and the two first catabolic enzymes, arginase and ornithine aminotransferase, were in the "soluble" fraction of the cell.
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PMID:Arginine metabolism in Saccharomyces cerevisiae: subcellular localization of the enzymes. 20 32

In a study of 4 enzymatic activities in human blood mononuclear cells before and immediately after standard maximal exercise test (25 min) on treadmill we noted: (1) a significant decrease in the activity of the pyruvate dehydrogenase complex (PDHc); (2) a significant increase in the activity of the citrate synthase (CS); and (3) no significant changes in the activities of cytochrome c oxydase and succinate cytochrome reductase. Although non-specifically stimulated (antigen or even mitogen), the blood mononuclear cells responded metabolically to muscular exercise. Pyruvate dehydrogenase (PDHc) activity of blood mononuclear cells appeared to decrease via enzyme interconversion regulation of PDHc. It is not known if these changes can be linked to the studies indicated altered immune function after a single bout of exercise.
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PMID:Blood mononuclear cells energy metabolism response to muscular exercise. 166 53

Considered are our own data and those found in literature on the properties of yeast mutants impaired in their ability to utilize methanol as sole carbon and energy source; hypotheses about the role of alcohol oxidase and citrate synthase in biogenesis of peroxisomes are proposed. It has been proved that formaldehyde reductase participates in the control of the formaldehyde level in the cell. Properties of mutants defective in the catabolite repression and inactivation of enzymes of methanol metabolism are described. The existence of several autonomous mechanisms of the catabolite repression of alcohol oxidase has been shown. It has been found, that the induction of glyoxysomal enzymes of C2-metabolism is repressed by methanol in the ecr1 mutant of Pichia pinus with the affected repression of alcohol oxidase by ethanol. Data are presented on the regulatory properties of the recently discovered acidification system of the medium induced by methanol. Such acidification occurs due to symport extrusion of protons and formate anions from the cells.
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PMID:Genetic control of methanol utilization in yeasts. 306 50

Muscle biopsy samples were collected from the middle gluteal muscle of seven horses undergoing a nine-month endurance training programme. Samples were collected before the programme began and again after three, six and nine months of training. A fifth sample was collected three months after training ceased. Serial muscle sections were reacted histochemically for myosin adenosine triphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) pre-incubation, and muscle fibres identified as type I, IIA, IIB or IIC. The oxidative capacity of individual fibres was assessed, using the reduced nicotinamide dinucleotide tetrazolium reductase stain, and the number of intermyofibrillar capillaries adjacent to each fibre was counted after staining, using the alpha-amylase periodic acid Schiff technique. Biochemical analyses involved the fluorometric measurement of the enzymes citrate synthase, 3-hydroxy acyl CoA dehydrogenase and lactate dehydrogenase as markers of end terminal oxidative, beta oxidative and glycolytic potential, respectively. There was an increase in the percentage of type IIB fibres having high nicotinamide dinucleotide tetrazolium reductase staining after three months training. This increase persisted throughout the period of training and during the period without training. There was an increase in the number of capillaries adjacent to type IIB fibres after six and nine months training. These had returned to near pre-training numbers after three months without training. There were increases in the activities of citrate synthase and 3-hydroxy acyl CoA dehydrogenase after three months training. The activities of both enzymes continued to rise throughout training and the highest activities were attained after nine months.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of a nine-month endurance training programme on muscle composition in the horse. 367 37

Biopsy samples were obtained from the middle gluteal muscle of 10 Thoroughbred horses undergoing a commercial race-training program. Samples were obtained before the program began and again after 6 and 12 weeks of training. All horses had raced at least once by the 12th week of training. Serial sections of muscle were examined histochemically for myosin adenosinetriphosphatase after either acid (pH 4.3 and 4.6) or alkaline (pH 10.3) preincubation, and then muscle fibers were identified as types I, IIA, IIB, or IIC. The oxidative capacity of individual fibers was assessed, using the reduced nicotinamide dinucleotide tetrazolium-reductase stain, and the number of intermyofibrillar capillaries adjacent to each fiber were counted after staining, using the alpha-amylase-periodic acid-Schiff technique. Biochemical analyses involved the fluorometric measurement of 3 enzymes--citrate synthase, 3-hydroxy-acyl coenzyme A dehydrogenase, and lactate dehydrogenase--as markers of end terminal oxidative, beta-oxidative, and glycolytic potentials, respectively. Changes in fiber-type percentages did not occur in response to training. There was a significant (P less than 0.01) increase in the percentage of type IIB fibers, having high nicotinamide dinucleotide-tetrazolium reductase staining after 12 weeks of training. Alterations in the number of capillaries adjacent to each fiber type did not occur during the training period. There were increases in the activities of both citrate synthase and 3-hydroxy-acyl coenzyme A dehydrogenase after 6 weeks (P less than 0.05) and 12 weeks (P less than 0.001) of training. Alterations in the activity of lactate dehydrogenase did not occur in response to training.
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PMID:Effects of training on muscle composition in horses. 394 89

Kinetic studies of the individual reaction of pig heart pyruvate dehydrogenase complex (pyruvate dehydrogenase (pyruvate:lipoamide oxidoreductase (decarboxylating and acceptor-acetylating), EC 1.2.4.1); dihydrolipoamide reductase(NAD+) (NADH:lipoamide oxidoreductase, EC 1.6.4.3); dihydrolipoamide acetyltransferase (acetyl-CoA:dihydrolipoamide S-acetyltransferase, EC 2.3.1.12)), citrate synthase (citrate oxaloacetate-lyase (pro-3S-CH2COO- leads to acetyl-CoA), EC 4.1.3.7) and the pyruvate dehydrogenase complex-citrate synthase coupled system show that the KmCoA value of pyruvate dehydrogenase complex and KmCoASAc value of citrate synthase decrease in the coupled system when compared to those in the individual enzyme reactions. The explanation for this interaction may be an association between the two enzymes. When it was centrifuged with 150 000 x g for 140 min, 30% of the citrate synthase sedimented in the presence of the pyruvate dehydrogenase complex, while no sedimentation was observed in the absence of the pyruvate dehydrogenase complex. Sedimentation of cytoplasmic malate dehydrogenase, phosphotransacetylase, hemoglobin and Blue albumin were negligible under the same condition. In gel chromatography experiments a significant peak of citrate synthase activity co-migrated with the pyruvate dehydrogenase complex peak. This observation also suggests the possible association of two enzymes.
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PMID:Interaction between the pyruvate dehydrogenase complex and citrate synthase. 721 36

Muscle cell fiber types in gracilis, rectus femoris, and long head of triceps brachii muscles of ferrets and dogs were identified on serial sections stained for myosin ATPase after preincubation at pH values of 9.8, 4.6, and 4.3 and for NADH-tetrazolium reductase (NADH-TR) activity. Although fiber types I and II were identified, the ATPase stain did not demonstrate classic type IIA/IIB fiber differences in either species. However, two type II fiber subtypes could be distinguished in the ferret because they differed slightly in staining intensity with ATPase at pH 4.3 and markedly with NADH-TR. One ferret type II fiber (designated II dark or IID) was smaller, slightly darker on ATPase, more oxidative on NADH-TR, and comprised more muscle volume than the other type II fiber (designated II light IIL). The IID fibers of ferret may represent the IID/X fibers of other authors. Both ferret type II fiber subtypes stained darker at pH 4.3 than canine II fibers. The NADH-TR staining indicated high oxidative activity in canine and ferret type I fibers. In contrast, type II fibers in the dog and IIL fibers in the ferret were moderately oxidative. Canine type IIC fibers were intermediate between type I and type II, whereas in the ferret, type IIC fibers were highly oxidative, as were type IID fibers. Ferret muscles are more oxidative than canine muscles according to NADH-TR staining. Also, ferret muscles possess 40-100% higher citrate synthase activity as compared to canine muscles.
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PMID:Comparison of muscle cell fiber types and oxidative capacity in gracilis, rectus femoris, and triceps brachii muscles in the ferret (Mustela putorius furo) and the domestic dog (Canis familiaris). 769 Oct 36

1. Treatment of isolated rat liver mitochondria with methyl methacrylate (MM) produced membrane disruption as evidenced by the release of citrate synthase, and changes in the ultrastructure of mitochondria. 2. At concentration 0.1%, MM uncoupled oxidative phosphorylation as evidenced by stimulation of state 4 respiration supported either by pyruvate plus malate or succinate (+rotenone) and ATP-ase activity in intact mitochondria. 3. At concentration 1% MM stimulated ATP-ase activity in intact mitochondria and succinate (+ rotenone) oxidation at state 4 and was without effect on this substrate oxidation at state 3. 4. MM inhibited pyruvate plus malate oxidation either at state 3 or in the presence of uncoupling agents. 5. MM inhibited the NADH oxidase of electron transport particles at a concentration which failed to inhibit either succinic oxidase or the NADH-ferricyanide reductase activity. 6. The data presented suggest that in the isolated mitochondria MM inhibits NADH oxidation in the vicinity of the rotenone sensitive site of complex I. 7. The general conclusion is that MM may block an electron transport and to uncouple oxidative phosphorylation in rat liver mitochondria. The overall in vitro effect would be to prevent ATP synthesis which could result in cell death under in vivo conditions.
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PMID:Effect of methyl methacrylate on mitochondrial function and structure. 798 36

We report the effect of the 11,778 and 3460 base pair mitochondrial DNA mutations, found in Leber's hereditary optic neuropathy (LHON), on platelet mitochondrial respiratory chain enzyme activity. We measured respiratory chain enzyme activities in platelets from 4 patients with the 3460 mutation, 17 patients with the 11,778 mutation and compared them with those of 41 healthy age-matched controls. We observed a 67% (P < 0.001) reduction in the mean NADH CoQ1 reductase (complex I) activity of the 3460 group compared to the control group. It has been shown previously that platelet mitochondrial biochemistry is affected by cigarette smoking. A significant reduction (25%, P < 0.03) in the mean complex I activity of the 11,778 group was only observed when the non-smokers within that group were compared to the non-smoking controls. The effect of smoking observed in this study may explain why previous workers have not observed a decrease in complex I activity associated with the 11,778 mutation. There was no significant change in the activity of complexes II/III or IV with either of these mutations. There was a significant increase (26%, P < 0.008) in citrate synthase (CS) activity with the non-smoking 11,778 group compared to the non-smoking control group, rising to 40% (P < 0.002) in those with this mutation who smoked. This reflects an increase in mitochondrial mass with the 11,778 mutation. This effect was not observed with the 3460 mutation even though the complex deficiency was much more severe.
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PMID:Platelet mitochondrial function in Leber's hereditary optic neuropathy. 819 7

To investigate energy metabolism in migraine, we determined platelet mitochondrial enzyme activities in 40 patients with migraine with aura and in 40 patients with migraine without aura during attack-free intervals and in 24 healthy control subjects. NADH-dehydrogenase, citrate synthase and cytochrome-c-oxidase activities in both patient groups were significantly lower than in controls (p < 0.01), while NADH-cytochrome-c-reductase activity was reduced only in migraine with aura (p < 0.01). No alteration in succinate-dehydrogenase was observed. Monoamine-oxidase activity differed between sexes (p < 0.05) but within each sex group no difference was observed between patients and controls. We hypothesize that the defect in mitochondrial enzymes observed indicates a systemic impairment of mitochondrial function in migraine patients.
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PMID:Abnormal platelet mitochondrial function in patients affected by migraine with and without aura. 820 18


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