Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.1.1.1 (alcohol dehydrogenase)
 9,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of aqueous organic cryosolvents on the structural and catalytic properties of horse liver alcohol dehydrogenase (liver alcohol dehydrogenase) have been investigated. The cosolvents studied were ethanol, methanol, dimethyl sulfoxide, and dimethylformamide. All show potential as cosolvents for cryoenzymological investigations of the catalytic action of liver alcohol dehydrogenase. Limitations due to the formation of abortive complexes, or the cosolvent acting as a substrate were considered. Possible adverse structural effects of the cosolvents were ascertained by utilizing the intrinsic fluorescent properties of the enzyme. Catalytic effects, as inferred from steady state kinetic studies, were determined from both the oxidation of ethanol and the reduction of p-nitroso-N,N-dimethylaniline, a chromophoric aldehyde analog. It is concluded that each of these solvent systems may be useful for studying certain aspects of the liver alcohol dehydrogenase catalytic mechanism at subzero temperatures. Thus, although the formation of ternary enzyme-cosolvent complexes may restrict the use of cosolvents in some experiments, no apparent adverse effects are observed on the enzyme structure, coenzyme binding, or catalytic reactions. A number of interesting features were observed. For example, fluorescence titration of the native enzyme near 0 degrees C in either aqueous solution or 50% dimethyl sulfoxide revealed pK values in the vicinity of 10.5 and 12.5, in contrast to the previously reported single pK of 9.2 observed in aqueous solution at 25 degrees C.
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PMID:The effect of cryosolvents on the spectral and catalytic properties of liver alcohol dehydrogenase. 635 83

There is an astonishing array of microbial alcohol oxidoreductases. They display a wide variety of substrate specificities and they fulfill several vital but quite different physiological functions. Some of these enzymes are involved in the production of alcoholic beverages and of industrial solvents, others are important in the production of vinegar, and still others participate in the degradation of naturally occurring and xenobiotic aromatic compounds as well as in the growth of bacteria and yeasts on methanol. They can be divided into three major categories. (1) The NAD- or NADP-dependent dehydrogenases. These can in turn be divided into the group I long-chain (approximately 350 amino acid residues) zinc-dependent enzymes such as alcohol dehydrogenases I, II, and III of Saccharomyces cerevisiae or the plasmid-encoded benzyl alcohol dehydrogenase of Pseudomonas putida; the group II short-chain (approximately 250 residues) zinc-independent enzymes such as ribitol dehydrogenase of Klebsiella aerogenes; the group III "iron-activated" enzymes that generally contain approximately 385 amino acid residues, such as alcohol dehydrogenase II of Zymomonas mobilis and alcohol dehydrogenase IV of Saccharomyces cerevisiae, but may contain almost 900 residues in the case of the multifunctional alcohol dehydrogenases of Escherichia coli and Clostridium acetobutylicum. The aldehyde/alcohol oxidoreductase of Amycolatopsis methanolica and the methanol dehydrogenases of A. methanolica and Mycobacterium gasti are 4-nitroso-N,N-dimethylaniline-dependent nicotinoproteins. (2) NAD(P)-independent enzymes that use pyrroloquinoline quinone, haem or cofactor F420 as cofactor, exemplified by methanol dehydrogenase of Paracoccus denitrificans, ethanol dehydrogenase of Acetobacter and Gluconobacter spp. and the alcohol dehydrogenases of certain archaebacteria. (3) Oxidases that catalyze an essentially irreversible oxidation of alcohols, such as methanol oxidase of Hansenula polymorpha and probably the veratryl alcohol oxidases of certain fungi involved in lignin degradation. This review deals mainly with those enzymes for which complete amino acid sequences are available. The discussion focuses on a comparison of their primary, secondary, tertiary, and quaternary structures and their catalytic mechanisms. The physiological roles of the enzymes and isoenzymes are also considered, as are their probable evolutionary relationships.
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PMID:Molecular characterization of microbial alcohol dehydrogenases. 818 33

Extracts of Gram-positive bacteria like Rhodococcus rhodochrous, Rhodococcus erythropolis and Amycolatopsis methanolica, but not those of several Gram-negative ones, showed dehydrogenase activity for ethanol as well as for methanol when 4-nitroso-N,N-dimethylaniline (NDMA) was used as electron acceptor. Chromatography of extracts of the first two organisms revealed one activity for both substrates, that of A. methanolica two activities, one of which is able to oxidize methanol and has been purified (Bystrykh, L.V., Govorukhina, N.I., van Ophem, P.W., Hektor, H.J., Dijkhuizen, L. and Duine, J.A., unpublished results). The other, indicated as NDMA-dependent alcohol dehydrogenase (NDMA-ADH), was purified to homogeneity. It is a trimeric enzyme consisting of subunits of 39 kDa and one firmly bound NAD as cofactor. Although NDMA-ADH shows structural similarity with the long-chain, zinc-containing, NAD(P)-dependent alcohol dehydrogenases with respect to the N-terminal sequence up to residue 41 (56% identity with horse liver alcohol dehydrogenase), the enzymes are catalytically different since NDMA-ADH is unable to use NAD(P)(H) as a coenzyme and NAD(P)-dependent alcohol dehydrogenases are inactive with NDMA (in the absence of NAD). Comparison of the NDMA-ADH properties with those of the methanol-oxidizing enzyme of A. methanolica, Mycobacterium gastri and Bacillus methanolica C1, and formaldehyde dismutase of Pseudomonas putida F61 revealed large differences in structural as well as catalytic properties, in spite of the fact that all are nicotinoproteins [enzymes which have bound NAD(P) as a cofactor]. It is concluded, therefore, that NDMA-ADH is a novel type of nicotinoprotein alcohol dehydrogenase.
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PMID:Nicotinoprotein [NAD(P)-containing] alcohol/aldehyde oxidoreductases. Purification and characterization of a novel type from Amycolatopsis methanolica. 838 13

The theory and practice of a novel spectrophotometric method for the enzymatic determination of NAD+ and NADH is described. The method can not discriminate between NAD+ and NADH, but determines the concentration of the sum of both nucleotides. The method is based on the bleaching of p-nitroso-N,N-dimethylaniline (NMDA) (epsilon 440 nm = 35400 M-1cm-1) with NADH, in the presence of ethanol and yeast alcohol dehydrogenase, under the conditions of enzymatic cycling (ethanol > NDNA > NAD/H). The initial rates of -NDMA bleaching are proportional to the concentration of NAD+ or NADH, in a broad range from 10 nM to 100 microM.
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PMID:A novel spectrophotometric method for the enzymatic determination of NAD+ and NADH. 885 49

The steady-state kinetics, product identification, stoichiometries, and solvent isotope effects of yeast alcohol dehydrogenase catalyzed reduction of p-nitroso-N,N-dimethylaniline (NDMA) by NADH, are reported. NDMA is enzymatically reduced to p-hydroxylamine-N,N-dimethylaniline, which is further enzymatically dehydrated to corresponding quinonediimine cation (QDI+). QDI+ undergoes nonenzymatic transformations. QDI+ is rapidly reduced by NADH to p-amino-N,N-dimethylaniline (ADMA). Also, QDI+ is readily dismutated with ADMA to form N,N-dimethyl-p-phenylenediamine radicals; radicals are stable under steady-state conditions, below pH 7.5. A complete kinetic mechanism for above reactions has been proposed.
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PMID:Yeast alcohol dehydrogenase catalyzed reduction of p-nitroso-N, N-dimethylaniline by NADH. 893 Jul 32

Synthesis of biosurfactants (surface-active substances, SAS) was investigated under the conditions of growth of Rhodococcus erythropolis IMV Ac-5017 and Acinetobacter calcoaceticus IMV B-7241 on hydrophobic (n-hexadecane, liquid paraffins, sunflower oil) and hydrophilic (ethanol) substrates depending on concentration (0.01-0.5 mM) and time of copper cations introduction in the medium. It is established that Cu2+ addition in the exponential phase of growth of the strains IMV B-7241 and IMV Ac-5017 on all studied substrates was accompanied by the increase of conventional concentration of SAS by 25-140% as compared with the indices in the medium without copper cations. Maximum synthesis intensification of SAS of A. calcoaceticus IMV B-7241 and R. erythropolis IMV Ac-5017 was observed in the case of Cu2+ introduction in the medium with hydrocarbons. The increase of SAS synthesis in the presence of copper cations is determined by their activating effect on activity of alkane hydroxylase of the both strains, as well as 4-nitroso-N,N-dimethylaniline-dependent alcohol dehydrogenase and enzymes of biosynthesis of surface active glyco-(phosphoenolpyruvate-synthetase) and aminolipids (NADP(+)-dependent glutamate dehydrogenase) in A. calcoaceticus IMV B-7241.
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PMID:[Effect of Cu2+ on synthesis of biosurfactants of Acinetobacter calcoaceticus IMV B-7241 and Rhodococcus erythropolis IMV Ac-5017]. 2351 34

The effect of yeast autolysate and microelements on synthesis of surface-active substances (SAS, biosurfactants) was investigated under cultivation of Acinetobacter calcoaceticus IMV B-7241 on various carbon substrates (n-hexadecane, ethanol, glycerol). The authors have shown a possibility to substitute the yeast autolysate and microelement mixture in the composition of ethanol- and n-hexadecane-containing media by copper sulfate (0.16 micromol/l) and iron sulfate (3.6 micromol/l), and in the medium with glycerol by 0.21 mmol/l of KCl, 38 micromol/l of zinc sulfate and 0.16 micromol/l of copper sulfate. Under such conditions of cultivation of the strain IMV B-7241 the SAS concentration exceeded that on the initial media, which contained the yeast autolysate and microelements, 1.2-1.6 times. The authors have also established the activating effect of low (0.01 mM) concentrations of Fe2+ on activity of the enzymes of biosynthesis of surface-active amino- (NADP-dependent glutamate dehydrogenase) and glycolipids (phosphoenolpyruvate(PhEP)-synthetase, PhEP-carboxykinase), as well as of anaplerotic reaction(PhEP-carboxylase). A necessity to introduce zinc cations into glycerol-containing medium is determined by their stimulating effect on activity of 4-dinitroso-N,N-dimethylaniline-dependent alcohol dehydrogenase--one of the enzymes of this substrate catabolism in A. calcoaceticus IMV B-7241.
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PMID:[Effect of growth factors and some microelements on biosurfactant synthesis of Acinetobacter calcoaceticus IMV B-7241]. 2447 9