Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: DrugBank:EXPT02288 (NADH)
 21,914 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The dose dependence of the acute effects of ethanol upon liver intermediary metabolism in vivo has been demonstrated in rats. Ethanol was given i.p. in doses of 0.69, 1.7, and 3.0 g/kg in equal volumes (20 ml/kg). The liver was freeze-clamped 120 min after injection, and multiple metabolites were measured in the perchloric acid extract of the tissue. Each group showed a significantly different pattern of metabolites, redox states, and phosphorylation potentials although the rate of ethanol disappearance, at least between the two highest dose groups, was not significantly different. The mitochondrial free [NAD+]/[NADH] ratios and the cytoplasmic free [NADP+]/[NADPH] ratio were paradoxically most reduced with the lowest dose of ethanol and became progressively more oxidized with increasing dose. Once established, the differences in these ratios between the groups tended to persist with time, relatively independent of the concentration of ethanol. In a somewhat different pattern, the phosphorylation potential ([ATP]/[ADP][P1]) remained at the control level in the low-dose group but was significantly elevated in the two higher-dose groups. The results, therefore, show distinct and complicated dose-dependent patterns of intermediary metabolism that cannot be explained completely by any one hypothesis but that imply significant dose-dependent effects of ethanol upon intermediary metabolism not directly related to NADH production.
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PMID:Dependence on dose of the acute effects of ethanol on liver metabolism in vivo. 0 Apr 22

The effect of NADH, succinate and ATP on the sensitivity of a number of energy-dependent functions of submitochondrial particles ot phospholipases A, C and D has been studied. It has been shown that in the conditions of oxidation of NADH and succinate by oxygen and also of ATP hydrolysis, the decrease in the phosphorylating activity of the particles under the action of phospholipases C and D accelerates. No such acceleration has been observed with phospholipase A. For other two functions, i. e. reverse electron transfer (ATP-dependent NAD+ reduction by succinate) and ATP-dependent transhydrogenase reaction the results proved to be different. Oxidizable substrates and ATP promoted the maintenance of these functions in the presence of phospholipase A, but did not retard their suppression by phospholipases C and D. The effects of NADH, succinate and ATP on the sensitivity of different energy-dependent functions of submitochondrial particles to phospholipases A, C and D could be removed by the uncoupling agent carbonyl cyanide-m-chlorophenyl hydrazone. The conclusion is made that the effects revealed are associated with an increase in the sensitivity of coupling sites II PAND/OR III to phospholipases C and D and with a decrease in the sensitivity of sites I and IV to phospholipase A on energization of submitochondrial particles.
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PMID:[The effect of oxidazable substrates and ATP on the sensitivity of certain energy-dependent functions submitochondrial particles to phospholipases A, C and D]. 0 Nov 16

1. The existence of two different D-glucose-6-phosphate dehydrogenases in Pseudomonas fluorescens has been demonstrated. Based on their different specificity and their different metabolic regulation one enzyme is appointed to the Entner-Doudoroff pathway and the other to the hexose monophosphate pathway. 2. A procedure is described for the isolation of that D-glucose-6-phosphate dehydrogenase which forms part of the Entner-Doudoroff pathway (Entner-Doudoroff enzyme). A 950-fold purification was achieved with an overall yield of 44%. The final preparation, having a specific activity of about 300 mumol NADH formed per min per mg protein, was shown to be homogeneous. 3. The molecular weight of the Entner-Doudoroff enzyme has been determined to be 220000 by gel permeation chromatography, and that of the other enzyme (Zwischenferment) has been shown to be 265000. 4. The pI of the Entner-Doudoroff enzyme has been shown to be 5.24 and that of the Zwischenferment 4.27. The Entner-Doudoroff enzyme is stable in the range of pH 6 to 10.5 and shows its maximal activity at pH 8.9. 5. The Entner-Doudoroff enzyme showed specificity for NAD+ as well as for NADP+ and exhibited homotropic effects for D-glucose 6-phosphate. It is inhibited by ATP which acts as a negative allosteric effector. Other nucleoside triphosphates as well as ADP are also inhibitory. 6. The enzyme catalyzes the transfer of the axial hydrogen at carbon-1 of beta-D-glucopyranose 6-phosphate to the si face of carbon-4 of the nicotinamide ring and must be classified as B-side stereospecific dehydrogenase.
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PMID:D-glucose-6-phosphate dehydrogenase (Entner-Doudoroff enzyme) from Pseudomonas fluorescens. Purification, properties and regulation. 0 Dec 57

Citrate synthase activity of Saccharomyces cerevisiae was determined by a radioactive assay procedure and the reaction product, 14C-citric acid, was identified by chromatographic techniques. ATP, d-ATP, GTP and NADH were most inhibitory to the citrate synthase invitro. The activity was inhibited to a lesser extent by ADP, UTP, and NADP whereas, AMP and CTP were much less inhibitory. NADH, like NAD, glutamic acid, glutamine, arginine, ornithine, proline, aspartic acid and alpha-ketoglutarate exhibited no inhibition. These results have been discussed in the light of the role of citrate synthase for the energy metabolism and glutamic acid biosynthesis.
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PMID:Regulation of citrate synthase activity of Saccharomyces cerevisiae. 0

The molar absorptivity of NADH at 340 nm has been determined by an indirect procedure in which high-purity glucose is phosphorylated by ATP in the presence of hexokinase, coupled to oxidation of the glucose-6-phosphate by NAD+ in the presence of glucose-6-phosphate dehydrogenase. The average value from 85 independent determinations is 6317 liter mol-1 cm-1 at 25 degrees C and pH 7.8. The overall uncertainty is -4.0 to +5.5 ppt (6292 to 6352 liter mol-1 cm-1), based on a standard error of the mean of 0.48 ppt and an estimate of systematic error of -2.6 to +4.1 ppt. Effects of pH, buffer, and temperature on the molar absorptivity are also reported.
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PMID:Determination of the molar absorptivity of NADH. 0 88

A monooxygenase isolated from 5-day old etiolated Vinca rosea seedlings was shown to catalyze the hydroxylation of the monoterpene alcohols, geraniol and nerol, to their corresponding 10-hydroxy derivatives. Hydroxylase activity was inpendent upon NADPH (neither NADH nor combination of NADH, NADP+ and ATP served as substitutes) and O2. Geraniol hydroxylation was enhanced by dithiothreitol (monothiols were less effective) and inhibited by phospholipases, thiol reagents, metyrapone, and cytochrome c, as well as other inhibitors of cytochrome P-450 systems. Geraniol was hydroxylated at a faster rate than nerol, but the alcohols possessed similar apparent Km values. The membrane-bound hydroxylase was solubilized by treatment with sodium cholate, Renex-30, or Lubrol-WX. Cholate-treated enzyme was resolved by DEAE-cellulose chromatography and reconstitution of the hydroxylase was effected utilizing different fractions containing cytochrome P-450, a NADPH-cytochrome c reductase, and lipid.
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PMID:Characterization of a cytochrome P-450 dependent monoterpene hydroxylase from the higher plant Vinca rosea. 0 9

1. A soluble protein with a molecular weight of 11-12-10(3) has been isolated from bovine-heart mitochondria, which stimulates the following ATP-dependent reactions of submitochondrial particles treated with 0.6 mM EDTA and 1 M NH4OH: reverse electron transfer from succinate to NAD, transhydrogenation from NADH to NADP, and ATP-Pi exchange. The factor has no effect on the NADH oxidase, succinate oxidase and ATPase activities of the particles. 2. The stimulatory effect of the factor in the ATP-dependent reduction of NAD by succinate is 12 mumol-min-1-mg-1 of the factor protein. However, the NH4OH-EDTA treated particles are saturated for maximal activation of the above reaction by very small amounts of the factor (about 20-40 mug factor per mg particle). 3. Electrophoresis of the factor preparation on polyacrylamide gels showed a single protein band plus a nonprotein material which moved at the dye front and was weakly stained with Coomassie Blue. The protein was shown to be required for activation of the particles; whether the fast-moving, nonprotein material is also required is not known. 4. The factor is inhibited by mercurials and N-ethylmaleimide. The former, but not the latter, inhibition is completely reversed by 1,4-dithiothreitol. 5. The NH4OH-EDTA treated particles are also stimulated by rutamycin up to about 0.1 nmol of rutamycin per mg particle; higher rutamycin concentrations inhibit. Depending on the particle preparation, the factor stimulates up to about 3 nmol per mg particle, but does not inhibit at higher concentrations. In addition, under certain conditions in which appropriate concentrations of rutamycin fail to stimulate the particles, the factor still does.
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PMID:Purification and properties of a low molecular weight protein factor of mitochondrial energy-linked functions. 0 97

The purpose of this work was in investigate the capability of cell extracts of Escherichia coli and E. coli treated with colicin K to catalyze the following energy-dependent reverse transhydrogenase reaction: NADP + NADH + ATP in equilibrium NADPH + NAD +ADP + Pi. Under anaerobic conditions this reaction requires the presence of a specific portion of the electron transport chain, a functional energy coupling system, including an adenosine triphosphatase, enzyme, and ATP as energy source. The ATP-linked reaction was partially inhibited in French press extracts of E. coli K-12 C600 cells that had been pretreated with colicin K but not in extracts from similarly treated cells of a colicin-tolerant mutant. Ultracentrifugation of extracts yielded particulate fractions competent in catalyzing the reaction; this reaction is substantially inhibited in fractions from colicin-treated cells. The extent of inhibition increased with increasing concentration of colicin. Supernatants also supported ATP-linked formation of NADPH, but this reaction was insensitive to the colicin effect. A comparison between the requirement of the reaction in supernatant and particulate fractions suggests that the reaction in the supernatant is different from the one inhibited by colicin. The ATP-hydrolyzing ability of particulate fractions from the control or treated bacteria was identical. Likewise, the electron transport chain was not affected by colicin treatment, as evidenced from lack of effect on NADH oxidase, succinic dehydrogenase, and NADPH-NAD transhydrogenase. It is concluded that colicin K interferes with the coupling of ATP the utilization of the intermediate for the ATP-linked transdehydrogenase reaction.
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PMID:Effect of colicin K on a membrane-associated, energy-linked function. 0 29

1. The effects of pH indicators on activities for ATP hydrolysis in the dark and ATP-Pi exchange in the dark were examined with chromatophores from Rhodospirillum rubrum. Of thirty-one pH indicators tested, eleven (metanil yellow, 2, 4-dinitrophenol, ethyl orange, bromocresol green, resazurin, neutral red, bromthymol blue, alpha-naphtholphthalein, o-cresolphthalein, phenolphthalein, and alizarin yellow G) almost completely inhibited the activities for ATP formation and ATP-Pi exchange at concentrations of 1 mM, and were studied in detail. 2. Of the eleven pH indicators, those other than alpha-naptholphthalein, o-cresolphthalein and phenolphthalein, when assayed at appropriate concentrations, inhibited ATP-Pi exchange, but not ATP hydrolysis. In ATP-Pi exchange, these eight pH indicators at the concentrations described above were competitive against Pi, and non-competitive against ATP. The remaining three kinds of pH indicators were non-competitive against either Pi or ATP, when assayed at concentrations of the dyes that inhibited both activities. 3. The amounts of pH indicators bound with chromatophores were measured. No correlation was found between the amounts of the bound dyes and the extents of their inhibition of either ATP formation or ATP-Pi exchange. 4. Ethyl orange (pKa=4.1) and 2, 4-dinitrophenol (pKa=3.9) stimulated ATP hydrolysis to the greatest extent. The latter dye was hardly bound with chromatophores. 5. The stimulatory effects of pH indicators on ATP hydrolysis were hardly affected by extraction of quinones from chromatophores. 6. Most of the pH indicators stimulated both succinate-cytochrome c2 and NADH-cytochrome c2 reductions in the dark. 7. The mechanism of uncoupling of the electron transfer system and the phosphorylation system by pH indicators and the mechanism of the coupling are discussed.
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PMID:Effects of pH indicators on various activities of chromatophroes of Rhodospirillum rubrum. 0 25

The citrate synthase activity of Acetobacter xylinum cells grown on glucose was the same as of cells grown on intermediates of the tricarboxylic acid cycle. The activity of citrate synthase in extracts is compatible with the overall rate of acetate oxidation in vivo. The enzyme was purified 47-fold from sonic extracts and its molecular weight was determined to be 280000 by gel filtration. It has an optimum activity at pH 8.4. Reaction rates with the purified enzyme were hyperbolic functions of both acetyl-CoA and oxaloacetate. The Km for acetyl-CoA is 18 mum and that for oxaloacetate 8.7 mum. The enzyme is inhibited by ATP according to classical kinetic patterns. This inhibition is competitive with respect to acetyl-CoA (Ki = 0.9 mM) and non-competitive with respect to oxaloacetate. It is not affected by changes in pH and ionic strength and is not relieved by an excess of Mg2+ ions. Unlike other Gram-negative bacteria, the A. xylinum enzyme is not inhibited by NADH, but is inhibited by high concentrations of NADPH. The activity of the enzyme varies with energy charge in a manner consistent with its role in energy metabolism. It is suggested that the flux through the tricarboxylic acid cycle in A. xylinum is regulated by modulation of citrate synthase activity in response to the energy state of the cells.
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PMID:Factors affecting the activity of citrate synthase of Acetobacter xylinum and its possible regulatory role. 0 2


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