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)

Treatment of submitochondrial particles (ETP) with trypsin at 0 degrees destroyed NADPH leads to NAD (or 3-acetylpyridine adenine dinucleotide, AcPyAD) transhydrogenase activity. NADH oxidase activity was unaffected; NADPH oxidase and NADH leads to AcPyAD transhydrogenase activities were diminished by less than 10%. When ETP was incubated with trypsin at 30 degrees, NADPH leads to NAD transhydrogenase activity was rapidly lost, NADPH oxidase activity was slowly destroyed, but NADH oxidase activity remained intact. The reduction pattern by NADPH, NADPH + NAD, and NADH of chromophores absorbing at 475 minus 510 nm (flavin and iron-sulfur centers) in complex I (NADH-ubiquinone reductase) or ETP treated with trypsin at 0 degrees also indicated specific destruction of transhydrogenase activity. The sensitivity of the NADPH leads to NAD transhydrogenase reaction to trypsin suggested the involvement of susceptible arginyl residues in the enzyme. Arginyl residues are considered to be positively charged binding sites for anionic substrates and ligands in many enzymes. Treatment of ETP with the specific arginine-binding reagent, butanedione, inhibited transhydrogenation from NADPH leads to NAD (or AcPyAD). It had no effect on NADH oxidation, and inhibited NADPH oxidation and NADH leads to AcPyAD transhydrogenation by only 10 to 15% even after 30 to 60 min incubation of ETP with butanedione. The inhibition of NADPH leads to NAD transhydrogenation was diminished considerably when butanedione was added to ETP in the presence of NAD or NADP. When both NAD and NADP were present, the butanedione effect was completely abolished, thus suggesting the possible presence of arginyl residues at the nucleotide binding site of the NADPH leads to NAD transhydrogenase enzyme. Under conditions that transhydrogenation from NADPH to NAD was completely inhibited by trypsin or butanedione, NADPH oxidation rate was larger than or equal to 220 nmol min-1 mg-1 ETP protein at pH 6.0 and 30 degrees. The above results establish that in the respiratory chain of beef-heart mitochondria NADH oxidation, NADPH oxidation, and NADPH leads to NAD transhydrogenation are independent reactions.
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PMID:Oxidation of NADPH by submitochondrial particles from beef heart in complete absence of transhydrogenase activity from NADPH to NAD. 0 Mar 95

Certain properties of the rat liver cell nuclei NAD-glycohydrolase (EC 3.2.2.5) were investigated. It is established that its highest activity is at 37 degrees with activation energy equal to 9480 cal/M and with factor Q10 equal to 1.5. The enzyme pH optimum in 0.2 M tris acetate is equal to 6.5 and in 0.2 potassium phosphate - 7.5. It was shown that the enzyme manifests its strict specificity only with beta-NAD, and it hardly decomposes NADP without affecting NADH, NADPH and NMN. The apparent Km value of the enzyme with respect to NAD is established. Isonicotinic acid hydrazide, nicotinamide and to the less extent nicotinic acid inhibit the enzymatic activity of nuclei. EDTA, EGTA, p-CMB, mercaptoethanol do not cause any changes in the rat liver cells nuclei NADase activity.
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PMID:[Properties of NAD-glycohydrolase of the nuclei of the liver cells of rats]. 0 Aug 30

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 effect of a single interaperitoneal injection (6 mg/kg body weight) of aflatoxin B1 in propylene glycol on pyridine nucleotides and NDP linked dehydrogenases was studied 24 h after administration of the toxin. The liver showed a decrease in total proteins and pyridine nucleotides though levels of NADP and NADPH remained unchanged. Levels of NAD and NADH were decreased. The activities of hepatic of hwpRIX of hepatic malate dehydrogenase (MDH) and isocitrate dehydrogenase (ICDH) were not altered though ICDH showed an increase when expressed on protein basis. However, there was a significance decrease in the activity of combined HMP dehydrogenases. Adipose tissue showed increased activities of the HMP dehydrogenasess.
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PMID:Effect of aflatoxin B1 on pyridine nucleotides and NADP linked dehydrogenases. 0 75

1) Glucose dehydrogenase from Bacillus megaterium has been purified to a specific activity of 550 U per mg protein. The homogeneity of the purified enzyme was demonstrated by gel electrophoresis and isoelectric focusing. 2) The amino acid composition has been determined. 3) The molecular weight of the native enzyme was found to be 116000 by gel permeation chromatography, in good agreement with the values of 120000 and 118000, which were ascertained electrophoretically according to the method of Hedrick and Smith and by density gradient centrifugation, respectively. 4) In the presence of 0.1% sodium dodecylsulfate and 8M urea, the enzyme dissociates into subunits with a molecular weight of 30000 as determined by dodecylsulfate gel electrophoresis. These values indicate that the native enzyme is composed of four polypeptide chains, each probably possessing one coenzyme binding site, which can be concluded from fluorescent titration of the NADH binding sites. 5) In polyacrylamide disc electrophoresis, samples of the purified enzyme exhibit three bands of activity, which present the native (tetrameric) form of glucose dehydrogenase and two monomeric forms (molecular weight 30000), arising under the conditions of pH and ionic strength of this method. 6) The enzyme shows a sharp pH optimum at pH 8.0 in Tris/HCl buffer, and a shift of the pH optimum to pH 9.0 in acetate/borate buffer. The limiting Michaelis constant at pH 9.0 for NAD is 4.5 mM and 47.5 mM for glucose. The dissociation constant for NAD is 0.69 mM. 7) D-Glucose dehydrogenase is highly specific for beta-D-glucose and is capable of using either NAD or NADP. The enzyme is insensitive to sulfhydryl group inhibitors, heavy metal ions and chelating agents.
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PMID:D-glucose dehydrogenase from Bacillus megaterium M 1286: purification, properties and structure. 0 30

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

Inositol biosynthesis was studied in soluble, cell extracts of a wild-type (Ino) strain of Saccharomyces cerevisiae. Two reactions were detected: (i) conversion of D-glucose-6-phosphate to a phosphorylated form of inositol, presumably inositol-1-phosphate (IP synthethase, EC5.5.1.4), and (ii) conversion of phosphorylated inositol to inositol (IP phosphatase, EC3.1.3.25). The in vitro rate of conversion of glucose-6-phosphate to inositol was proportional to incubaion time and enzyme concentration. The pH optimum was 7.0. The synthesis of inositol required oxidized nicotinamide adenine dinucleotide (NAD) and was stimulated byNH4C1 and MgC12. NADP substituted poorly for NAD, and NADH inhibitedthe reaction. Phosphorylated inositol accumulated in the absence of MgC12, suggesting that inositol-phosphate is an intermediate in the pathway and that Mg ions stimulate the dephosphorylation of inositol-phosphate. IP synthetase was inhibited approximately 20% in the presence of inositol in the reaction mixture at concentrations exceeding 1 mM. The enzyme was repressed approximately 50-fold when inositol was present in the growth medium at concentrations exceeding 50 muM. IP synthetase reached the fully repressed level approximately 10 h after the addition of inositol to logarithmic cultures grown in the absence of inositol. The specific activity of the enzyme increased with time in logarithmically growing cultures lacking inositol andapproached the fully depressed level as the cells entered stationary phase.
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PMID:Control of inositol biosynthesis in Saccharomyces cerevisiae: properties of a repressible enzyme system in extracts of wild-type (Ino+) cells. 0 23

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

The NADP-linked malic enzyme from Halobacterium cutirubrum is strongly inhibited by acetyl-CoA and NADH, and rather weakly inhibited by oxaloacetate and glyoxylate, in the presence of very high KCl concentrations (3 M), considered physiological for the extremely halophilic bacteria.
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PMID:On the regulatory properties of a halophilic malic enzyme from Halobacterium cutirubrum. 0 87

1. When [3H]rifampicin is incubated with rat liver microsomes or rat liver homogenate, minor amounts are bound irreversibly to protein. This effect does not depend on the presence of NAD, NADH, NADP or NADPH. 2. Rifampicin is autoxidized at physiological pH. The product of autoxidation, rifampicin-quinone, if incubated with albumin, shows a much greater irreversible binding to the protein than the parent compound rifampicin. Hence it is concluded that rifampicin may bind irreversibly to proteins in a non-enzymic reaction after autoxidation to rifampicin-quinone. 3. Rifampicin-quinone also binds irreversibly to RNA and poly-L-lysine, if incubated with these compounds. This suggests that free amino groups of protein or RNA are involved in the binding. 4. 48 h after dosage of [3H]rifampicin (33 mg/kg) to rats, 29-2 +/- 4-1 (S.D.) pmol are bound irreversibly to 1 mg liver RNA, 15.8 +/- 8-1 pmol to 1 mg liver protein and 5-0 +/- 0-47 pmol to 1 mg protein in brain tissue. 5. Microsomal NADPH-cytochromcin-quinone to rifampicin. The KM of this reaction is 10(-4) M. Induction of the NADPH-cytochrome c reductase by pre-treatment of rats with 20 mg/kg rifampicin over 5 days results in a corresponding increase of increase of rifampicin-quinone reduction. 6. These results suggest that microsomal NADPH-cytochrome c reductase prevents accumulation of higher amounts of possibly toxic rifampicin-quinone by reduction to rifampicin.
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PMID:Implication of rifampicin-quinone in the irreversible binding of rifampicin to macromolecules. 0 22


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