Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.6.99.3 (diaphorase)
 5,903 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Biopsies from vastus lateralis muscle of male patients suffering from chronic ethanol abuse were studied with regard to histochemical reactions of ATPase and NADH-diaphorase; enzymatic activities of triosephosphate dehydrogenase (TPD), lactate dehydrogenase (LD), and cytochrome c oxidase (cytox); content of ATP, creatine phosphate, and glycogen; and volume fractions of fat, mitochondria, and fibrillar and extrafibrillar space. The results were compared with those from controls without known abuse of ethanol. The relative numbers of fibers were the same in two groups, but the size of the fast-twitch-glycolytic (white) fibers was diminished in the alcoholic group. The activities of TPD and LD were diminished in skeletal muscle of the alcoholics. This is most probably caused by the reduced amount of fast-twitch-glycolytic tissue, as there was a good correlation between this amount and the activity of the two enzymes. The activity of cytox was slightly lower in muscle of the alcoholics than in that of the controls. The volume fraction of mitochondria was lower in the alcoholic group than in the control group. Volume fractions of fat and fibrillar and extrafibrillar space were equal in the two groups. No significant differences were found in the amount of glycogen and ATP in the muscle of the two groups. However, the content of creatine phosphate is higher in the alcoholic group than in the control group.
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PMID:Effects of chronic ethanol abuse on structure and enzyme activities of skeletal muscle in man. 17 13

Palmitoyl CoA-glycerol-3-phosphate acyltransferase, phosphatidate phosphohydrolase, and phospholipase A were assayed in subcellular fractions of rat lung, including lamellar bodies, the putative site of storage and secretion of lung surfactant. The specific activity of each of these enzymes in lamellar bodies was relatively low and could be entirely accounted for by a small contamination of the lamellar bodies fraction by microsomes, as quantitated by the presence of the microsomal marker reduced triphosphopyridine nucleotide cytochrome c reductase. These data indicate that lamellar bodies are not the site of synthesis of the lipid component of pulmonary surfactant by pathways involving these enzymes.
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PMID:Lung lamellar bodies lack certain key enzymes of phospholipid metabolism. 17 33

The coordination structure of the iron-sulfur center of the nitrotyrosine and the aminotyrosine derivates of bovine adrenodoxin was investigated by electron paramagnetic resonance spectroscopy. The reduced form of both modified samples exhibited signals identical with those for the native protein at g= 1.94 and g=2.01. From these results together with optical absorption and chemical analyses, it was concluded that the coordination structure of the iron-sulfur chromophore for both the derivatives was identical with the binuclear tetrahedral structure of native adrenodoxin. The configuration of the iron-binding area in nitro- and amino-adrenodoxin was studied by ovserving the circular dichroism spectra between 350 and 600 nm. The maxima for the nitro or amino derivatives were all identical with those for the native protein but different in the magnitude of their molar ellipticity. The molar ellipticities at 440 nm were 45.8 X 10(3), 14.5 X 10(3), and 9.5 X 10(6) deg cm2 per mol of iron for native adrenodoxin, nitro or amino derivative, respectively. These results suggest that the chemical modification of the tyrosine residue causes a conformational change in the iron-binding area. We have previously reported that the enzymatic activities of these reconstituted nitro and amino derivatives toware cytochrome c reduction in the presence of adrenodoxin reductase and reduced nicotinamide adenine dinucleotide phosphate were 19 and 7% of native adrenodoxin, respectively. The cytochrome c reductase activities of nitro- and aminoadrenodixin were drastically affected by the ionic strength of the assay medium, as found in native adrenodoxin. Fluorometric titration of the reductase with aminoadrenodoxin revealed that aminoadrenodoxin forms a 1:1 molar complex with the reductase. These results suggest that both the nitro and amino derivatives form a complex with the reductase. The dissociation constants of nitro- and aminoadrenodoxin for the reductase were 6.1 X 10(-7)M and 3.3 X 10(-7) M at mu = 0.04 and 1.9 X 10(-6) M and 2.0 X 10(-6) M at mu = 0.20, respectively. Comparison of these values with those of native adrenodoxin (approximately 10(-9) M at mu = 0.04 and 2.2 X 10(-7) M at mu = 0.20) suggests that an increase in the dissociation constant for the reductase is responsible for the decreased electron transferring activity of the modified adrenodoxins.
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PMID:Studies on nitrotyrosine-82 and aminotyrosine-82 derivatives of adrenodoxin. Effects of chemical modification on the complex formation with adrenodoxin reductase. 18 Oct 49

The concentrations of cytochrome P-450 and the activities of aryl hydrocarbon [benzo(a)pyrene] hydroxylase (AHH) and reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase were measured in early (gray-white) and remodeled (brown) hyperplastic nodules induced in the livers of rats with 2-acetylaminofluorene and were compared to the values in control livers and in the liver surrounding the nodules. Cytochrome P-450 content of early (14 weeks) hyperplastic nodules is 30% of the activity of untreated control livers and 48% of the activity of the surrounding liver. AHH activity of the early nodules is 10% of the control activity and 33% of the activity in the surrounding nonnodular liver. Nicotinamide adenine dinucleotide phosphate-cytochrome c reductase activity in the microsomes of early nodules is 76% of the control activity and 78% of the activity in the surrounding liver. In the late remodeled nodules, (22 and 25 weeks), the cytochrome P-450 content is 40% of that of controls and AHH activity is 15% of the control activity. In primary hepatomas induced by 2-acetylaminofluorene, cytochrome P-450 content is 21% of that of controls, AHH activity is 11% of the activity of controls, and reductase is 50% of the control activity. These results, indicating a relative nodule deficiency in some of the cellular components believed to be important in the activation of hepatocarcinogens and hepatotoxins, offer one possible explanation for the relative resistance to carcinogen cytotoxicity of hyperplastic liver nodules.
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PMID:A relative deficiency of cytochrome P-450 and aryl hydrocarbon [benzo(a)pyrene] hydroxylase in hyperplastic nodules induced by 2-acetylaminofluorene in rat liver. 18 17

1. Intact and pure parenchymal and non-parenchymal cells were isolated from rat liver. The specific activities of several mitochondrial enzymes were determined in both parenchymal and non-parenchymal cell homogenates to characterize the mitochondria in these liver cell types. 2. In general the activities of mitochondrial enzymes were lower in non-parenchymal liver cells than in parenchymal cells. The specific activity of pyruvate carboxylase in non-parenchymal cells expressed as the percentage of that in parenchymal cells was onlu 2% for glutamate dehydrogenase 4.3% and for cytochrome c oxidase 79.4%. Monoamine oxidase, as an exception, has an equal specific activity in both cell types. 3. The activity ratio of pyruvate carboxylase at 10 mM pyruvate over 0.1 mM pyruvate is 3.35 for parenchymal cells and 1.50 for non-parenchymal cells. This indicates that non-parenchymal liver cells only contain the high affinity form of pyruvate carboxylase in contrast to parenchymal cells. 4. The ratio of glycerol-3-phosphate cytochrome c reductase over succinate cytochrome c reductase activity differs from parenchymal (0.01) and non-parenchymal cells (0.10). This might indicate that the glycerol-3-phosphate shuttle, which is important for the transport of reduction equivalents for cytosol to mitochondria is relatively more active in non-parenchymal cells than in parenchymal cells. 5. The activity pattern of mitochondrial enzymes in parenchymal and non-parenchymal cell homogenates indicates that these cell types contain different types of mitochondria. The presence of these different cell types in liver will therefore contribute to the heterogeneity of isolated rat liver mitochondria in which the mitochondria from non-parenchymal cells might be considered as "non-gluconeogenic".
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PMID:Different types of mitochondria in parenchymal and non-parenchymal rat-liver cells. 19 9

R-1 (1450g) and R-2 (25,000g) liver fractions from T/t6 and B6CBAF1 hybrid mice were analyzed for their protein content, mitochondria concentrations, and activities of three respiratory-chain enzymes of the mitochondrial inner membrane: cytochrome c oxidase (ferrocytochrome c: oxygen oxidoreductase, E.C. 1.9.3.1.), alpha-glycerophosphate dehydrogenase [L-glycerol-3-phosphate: (acceptor) oxidoreductase, E.C. 1.1.99.5], and succinate-cytochrome c reductase. Only cytochrome c oxidase activity, calculated as units per 10(10) mitochondria, was significantly lower in both R-1 and R-2 fractions of T/t6 mice. Cytochrome c oxidase activity varied greatly among T/t6 mice, as did their liver mitochondria concentrations and body weights. Cytochrome c oxidase activity in the R-1 fraction of T/t6 mice, averaged about 40% lower than in B6CBAF1 mice. alpha-Glycerophosphate dehydrogenase activity was often elevated in T/t6 mice, particularly in the R-2 fraction. The T/t locus, a complex genetic locus on chromosome 17, may contain genes important to the function and biogenesis of mitochondria.
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PMID:Cytochrome c oxidase activity in T/t6 (balanced lethal) mutant mice. 20 Feb 18

Experiments were conducted on rabbits. A study was made of the activity of the redox enzymes--glucose-6-phosphate dehydrogenase (G-6-PDH), lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), NAD-and NADP-diaphorases, cytochromeoxidase (CCO), alpha-glycerophosphate dehydrogenase (alpha-GPDH) in the supraoptic and paraventricular nuclei of the hypothalamus and the posterior lobe of the hypophysis under conditions of stimulation and removal of the superior cervical sympathetic ganglia. There was revealed a correlation between the activity of the tissue respiration enzymes (SDH, MDH, NAD- and NADP-diaphorase, CCO) and the functional condition of the hypothalamo-neurohypophysial neurosecretory system. However, the enzymes of the pentose-phosphate (G-6-PDH) and glycerophosphate shunt (alpha-GPDH) and also of the anaerobic way of oxidation (LDH) reacted nonspecifically on the induced effects.
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PMID:[Effect of removal and stimulation of the superior cervical sympathetic ganglia on the activity of oxidation-reduction enzymes in the neurosecretory cells of the anterior hypothalamus in rabbits]. 20 40

Differential centrifugation of suspensions of French-press-disrupted Rhodopseudomonas spheroides yielded a light particulate fraction that was different in many properties from the bulk membrane fraction. It was enriched in cytochrome c and had a low cytochrome b content. When prepared from photosynthetically grown cells this fraction had a very low specific bacteriochlorophyll content. The cytochrome c of the light particles differed in absorption maxima at 77K from cytochrome c2 attached to membranes; there was pronounced splitting of the alpha-band, as is found in cytochrome c2 free in solution. Potentiometric titration at A552--A540 showed the presence of two components that fitted an n = 1 titration; one component had a midpoint redox potential of +345mV, like cytochrome c2 in solution, and the second had E0' at pH 7.0 of +110 mV, and they were present in a ratio of approx. 2:3. Difference spectroscopy at 77K showed that the spectra of the two components were very similar. More of a CO-binding component was present in particles from photosynthetically grown cells. Light membranes purified by centrifugation on gradients of 5--60% (w/w) sucrose retained the two c cytochromes; they contained no detectable succinate-cytochrome c reductase or bacteriochlorophyll and very little ubiquinone, but they contained NADH-cytochrome c reductase and some phosphate. Electrophoresis on sodium dodecyl sulphate/polyacrylamide gels showed that the light membranes of aerobically and photosynthetically grown cells were very similar and differed greatly from other membrane fractions of R. spheroides.
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PMID:Properties of a cytochrome c-enriched light particulate fraction isolated from the photosynthetic bacterium Rhodopseudomonas spheroides. 21 23

The authors have studied the enzymhistochemical and ultrastructural pictures of tenocytes of adult human tendons. High succinate dehydrogenase, cytochrome oxidase, TPN-diaphorase, lactate dehydrogenase and glucose-6-phosphate dehydrogenase activity were found, as indicated both oxidativ, anaerobic and pentose-phosphate shung activity. Phosphorylase and glutamate dehydrogenase activity was medial, lipase and alcaline phosphatase activity was slight. In tenocytes well developed rough endoplasmic reticulum and GOLGI apparatus, large amount of free ribosomes were found.
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PMID:Histochemical and ultrastructural study of adult human tendon. 23 84

Different functional and structural properties of rat liver microsomes were studied during hepatocarcinogenesis induced by 0.25% DL-ethionine. During the first to fourth months of ethionine feeding, great decreases of cytochrome P-450 content, reduced nicotinamide adenine dinucleotide phosphate-dependent lipid peroxidation, and animopyrine demethylase activity occurred. No changes in the reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase activity were observed. These functional alterations were paralleled by an increase in membrane-free ribosomes and by changes in the relative proportions of phospholipid fatty acids in microsomes. After the end of ethionine feeding, when hyperplastic nodules and/or hepatomas were present, the above functional and structural parameters were studied in the latter tissues, as well as in surrounding nonodular liver. Decreases in cytochrome P-450 content, lipid peroxidation, and animopyrine demethylase activity were documented in hyperplastic nodules and hepatomas. In hepatomas, the alterations were more marked and decrease of reduced nicotinamide adenine dinucleotide phosphate-cytochrome c reductase activity was also found. All these functional parameters were quite normal in surrounding nonnodular liver. Similarly, alterations in phospholipid fatty acid composition disappeared in surrounding nonnodular liver, but they partially persisted in both hyperplastic nodules and hepatomas. In contrast, the increase in membrane-free ribosomes also occurred in surrounding nonnodular liver, although to a lower extent than in hyperplastic nodules and hepatomas. These data are discussed in relation to the problem of the cellular precursors of hepatomas.
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PMID:Functional and structural alterations of liver ergastoplasmic membranes during DL-ethionine hepatocarcinogenesis. 24 83


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