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)

Membrane vesicles isolated from Escherichia coli ML 308--225 have been analyzed by crossed immunoelectrophoresis, and immunoprecipitates corresponding to the following cellular components have been identified: ATPase (EC 3.6.1,3), two or three NADH dehydrogenases (EC 1.6.99.3), D-lactate dehydrogenase (EC 1.1.1.27), glutamate dehydrogenase (EC 1.4.1.4), dihydro-orotate dehydrogenase (EC 1.3.3.1), 6-phosphogluconate dehydrogenase (EC 1.1.1.43), polynucleotide phosphorylase (EC 2.3.7.8), beta-galactosidase (EC 3.2.1.23), lipopolysaccharide, and Braun's lipoprotein. The cellular origin of many of the vesicle immunogens is determined, and Braun's lipoprotein is used as a marker to quantitate the extent of outer membrane contamination (less than 3%). Membrane antigens are also characterized with regard to their amphiphilic or hydrophilic properties by charge-shift crossed immunoelectrophoresis. Furthermore, the following immunogens cross-react with components in membrane vesicles prepared from Salmonella typhimurium: one of the three NADH dehydrogenases, ATPase, polynucleotide phosphorylase, 6-phosphogluconate dehydrogenase, Braun's lipoprotein, and three unidentified antigens. In the accompanying paper [Owen, P., & Kaback, H. R. (1979) Biochemistry 18 (following paper in this issue)] quantitative immunoadsorption is utilized to establish the topology of the vesicles with respect to the distribution of antigens on the inner and outer faces of the membrane.
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PMID:Immunochemical analysis of membrane vesicles from Escherichia coli. 21 20

The antigenic architecture of membrane vesicles prepared from Escherichia coli ML 308--225 has been studied using crossed immunoelectrophoresis. Progressive immunoadsorption experiments conducted with control vesicles and with physically disrupted vesicles were used to monitor and quantitate the expression of 14 different immunogens. Eleven immunogens, including NADH dehydrogenase (EC 1.6.33.3), D-lactate dehydrogenase (EC 1.1.1.27), dihydro-orotate dehydrogenase (EC 1.3.3.1), 6-phosphogluconate dehydrogenase (EC 1.1.1.43), polynucleotide phosphorylase (EC 2.3.7.8), and beta-galactosidase (EC 3.2.1.23), exhibit minimal expression (10% or less) unless the vesicles are disrupted. Three unidentified antigens are expressed to a similar extent in untreated and disrupted vesicles. Consideration of these and other results [Owen, P., & Kaback, H. R. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 3148] in terms of membrane polarity, dislocation of antigens, and possible transmembrane orientation of some immunogens reveals that over 95% of the membrane in the vesicle preparations is in the form of sealed sacculi with the same orientation as the intact cell. Furthermore, antigens are distributed across the membrane in a highly asymmetric manner, indicating that dislocation of components from the inner to the outer surface of the membrane during vesicle preparation does not occur to an extent exceeding 10%.
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PMID:Antigenic architecture of membrane vesicles from Escherichia coli. 21 21

An Escherichia coli mutant (tolI) previously shown to be tolerant to colicins Ia and Ib is defective in several functions of the bacterial cytoplasmic membrane. When compared with its parental strain, X36, whole cells of tolI show reduced rates of respiration with succinate, malate, or lactate as the substrate but near-normal rates with glucose or glycerol. Cell membrane preparations prepared from tolI cells exhibit reduced succinate and D-lactate oxidase activity but elevated levels of reduced-form nicotinamide adenine dinucleotide (NADH) oxidase. tolI cells have reduced levels of succinate and D-lactate dehydrogenase but normal levels of NADH dehydrogenase. Glycerol-grown tolI cells and membrane vesicles prepared from such cells are defective in the active transport of several amino acids and thiomethyl-beta-D-galactoside; however, they accumulate higher levels of alpha-methylglucoside when compared with X36 whole cells or vesicles. Although tolI cells adsorb less colicin Ia at high colicin concentrations than do X36 cells, it is shown that the adsorption of an Ia molecule to tolI cells has a lower probability of eliciting cell death than does Ia adsorption to strain X36 cells. It is concluded that a single mutation can lead to an alteration in several aspects of cytoplasmic membrane function and colicin I sensitivity.
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PMID:Alterations in membrane function in an Escherichia coli mutant tolerant to colicins Ia and Ib. 110 88

D-Lactate in biological samples was converted into a strongly fluorescent substance in a one-vial reaction. It was first converted into the pyruvate hydrazone in the presence of D-lactate dehydrogenase, an NADH-reoxidation system using diaphorase, D,L-6,8-thioctamide and hydrazine. This hydrazone was then converted into 2-hydroxy-6,7-dimethoxy-3-methylquinoxaline by 1,2-diamino-4,5-dimethoxybenzene in 1 M hydrochloric acid, and the quinoxaline was extracted and measured fluorimetrically at 432 nm (excitation at 365 nm). The calibration curve for D-lactate was linear up to at least 100 nmol/ml of the assay mixture, with a determination limit of 2 nmol/ml. The quinoxaline was also analysed by high-performance liquid chromatography with fluorimetric detection. The calibration curve for D-lactate was linear from 500 fmol to 75 nmol in the reaction mixture. This method was 4000 times more sensitive than the fluorimetric method, and could determine D-lactate in blood plasma volumes of less than 1 microliter.
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PMID:Fluorimetric and high-performance liquid chromatographic determination of D-lactate in biological samples. 188 4

The effects of pentagalloylglucose (1,2,3,4,6-penta-O-galloyl-beta-D-glucose) on the aerobic electron transport system of Escherichia coli were studied. The activity of nicotineamide adenine dinucleotide (NADH) reductase was inhibited by pentagalloylglucose, but the activities of succinate dehydrogenase, D-lactate dehydrogenase, and ubiquinol-1 (Q1H2) oxidase were not susceptible to the inhibitor. Because the presence of two kinds of NADH dehydrogenase in respiratory chain of Escherichia coli has been reported, we examined the effect of galloylglucose independently on both NADH dehydrogenases. Pentagalloylglucose is potent and specific inhibitor of both NADH dehydrogenases. One of the NADH dehydrogenases (NADH dh II) is more sensitive to the inhibitor than the other (NADH dh I).
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PMID:Inhibitory effects of galloylglucose on nicotinamide adenine dinucleotide dehydrogenases of the aerobic respiratory chain of Escherichia coli. 218 79

D-Lactate in biological samples was converted into the hydrazone of pyruvate in the presence of D-lactate dehydrogenase, an NADH-reoxidation system using diaphorase, DL-6,8-thioctamide and hydrazine. The hydrazone was converted into 2-methylquinoxanol by o-phenylenediamine in hydrochloric acid, and then the quinoxanol was determined by high-performance liquid chromatography with fluorescence detection. The calibration curve of D-lactate was linear up to at least 60 nmol/ml, and the determination limit was 600 fmol. Using this method, D-lactate was determined in biological samples.
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PMID:Sensitive determination of D-lactic acid in biological samples by high-performance liquid chromatography. 324 81

Synthesis of the membrane-bound, flavin-linked D-lactate dehydrogenase of Escherichia coli has been studied by using a recombinant plasmid containing the dld gene [Young, I. G., Jaworowski, A., & Poulis, M. (1982) Biochemistry (following paper in this issue)]. Expression of the cloned dld gene was achieved either in vivo with transformed minicells or in vitro with a fractionated transcription/translation system. In both instances, a product is observed that is specifically immunoprecipitated by gamma-globulin prepared against the purified enzyme and comigrates with authentic D-lactate dehydrogenase on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Furthermore, the product is catalytically active and binds to membrane vesicles during or after synthesis. Thus, it seems likely that the protein is synthesized in mature form and binds to the membrane without a leader peptide sequence. Interestingly, addition of flavin adenine dinucleotide to the in vitro reaction mixtures causes a 2-fold increase in the synthesis of the enzyme, suggesting that the cofactor plays a regulatory role in the synthesis of the apoprotein. Finally, L factor, a protein involved in regulation of protein elongation, has an inhibitory effect on the expression of the dld gene and a stimulatory effect on the expression of the ndh gene (encoding NADH dehydrogenase).
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PMID:In vitro synthesis of the membrane-bound D-lactate dehydrogenase of Escherichia coli. 704 93

During attempts to clone the gene coding for the respiratory NADH dehydrogenase of Escherichia coli, two hybrid plasmids were constructed from E. coli chromosomal DNA [Young, I. G., Jaworowski, A., & Poulis, M. I. (1978) Gene 4, 25-36]. One of these plasmids, pIY1, derived from EcoRI-digested chromosomal DNA, was studied in detail and shown to possess the gene coding for the NADH dehydrogenase of the aerobic respiratory chain of E. coli. We now report the characterization of the other hybrid plasmid, pIY2, derived from HindIII-digested chromosomal DNA, and shown that it complements ndh mutants not by virtue of carrying the ndh gene but because it carries the gene coding for the respiratory D-lactate dehydrogenase. Cells carrying this hybrid plasmid overproduce the respiratory D-lactate dehydrogenase in their cell membranes by 15-20-fold with negligible activity appearing in the cytoplasm. This results in an amplification of the levels of the D-lactate oxidase. The amplified D-lactate oxidase activity, coupled with the pyridine nucleotide linked D-lactate dehydrogenase, apparently provides a new pathway for the oxidation of reduced nicotinamide adenine dinucleotide (NADH) in the cell, independent of the respiratory NADH oxidase.
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PMID:Cloning of the gene for the respiratory D-lactate dehydrogenase of Escherichia coli. 704 94

D-Lactate dehydrogenase, the starting enzyme for carbon and energy metabolism in dissimilatory sulfate-reducing bacteria, has been purified 36-fold from the soluble fraction of the sonicate of Desulfovibrio vulgaris, Miyazaki. The enzyme is specific for D-lactate (Km = 0.8 mM) and DL-2-hydroxybutyrate (probably its D-isomer) as the electron donor substrate. It reduces, in the presence of lactate, various artificial electron acceptors such as 1-methoxyphenazinium methyl sulfate, ferricyanide, tetrazolium dyes, methylene blue, and 2,6-dichlorophenol-indophenol. When 2 mol of ferricyanide was reduced, 1 mol of pyruvate was produced during the reaction. Among natural electron carriers, only cytochrome c-553 isolated from the same organism can be reduced by the enzyme. The ferric complex of pyridine-2,6-dicarboxylate can act as an electron acceptor if cytochrome c-553 is present in the reaction system. NAD+, NADP+, FAD, FMN, cytochrome c3, high-molecular-weight cytochrome, eucaryotic cytochromes c (yeast and horse) and O2 could not be reduced. The enzyme does not have any diaphorase activity. The D-lactate dehydrogenase of D. vulgaris must therefore be named D-lactate:ferricytochrome c-553 oxidoreductase [EC subclass 1.1.2]. A similar enzyme exists in the formate dehydrogenase-less mutant of D. vulgaris, Miyazaki, and in D. vulgaris, Hildenborough.
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PMID:D-lactate dehydrogenase of Desulfovibrio vulgaris. 727 46

An enzyme exhibiting NADH oxidase (diaphorase) activity was isolated from the hyperthermophilic sulfate-reducing anaerobe Archaeoglobus fulgidus. N-terminal sequence of the protein indicates that it is coded for by open reading frame AF0395 in the A. fulgidus genome. The gene AF0395 was cloned and its product was purified from Escherichia coli. Like the native NADH oxidase (NoxA2), the recombinant NoxA2 (rNoxA2) has an apparent molecular mass of 47 kDa, requires flavin adenine dinucleotide for activity, has NADH-specific activity, and is thermostable. Hydrogen peroxide is the product of bivalent oxygen reduction by rNoxA2 with NADH. The rNoxA2 is an oxidase with diaphorase activity in the presence of electron acceptors such as tetrazolium and cytochrome c. During purification NoxA2 remains associated with the enzyme responsible for D-lactate oxidation, the D-lactate dehydrogenase (Dld), and the genes encoding NoxA2 and Dld are in the same transcription unit. Together these results suggest that NADH oxidase may be involved in electron transfer reactions resulting in sulfate respiration.
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PMID:H(2)O(2)-forming NADH oxidase with diaphorase (cytochrome) activity from Archaeoglobus fulgidus. 1171 57


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