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 kinetics of the horse liver alcohol dehydrogenase (alcohol: NAD+ oxidoreductase EC 1.1.1.1) catalyzed metabolism of octanol and octanal to octanoic acid have been examined. On incubation of octanol with horse liver alcohol dehydrogenase in the presence of NAD+, NADH as well as octanal and octanoic acid were seen as the initial products. However, on continued incubation, the octanal concentration progressively decreased to where only negligible quantities were present in the incubation after 10 min. The production of NADH was biphasic. An initial phase was followed in about 2 min with a slower but linear rate of NADH production. The production of octanoic acid was approximately linear throughout the 10 min incubation period. Since octanal is an intermediate in the oxidation of octanol to octanoic acid, the ability of semicarbazide to inhibit the metabolism of octanol to octanoic acid was examined. At a concentration of semicarbazide which was 63 times the concentration of octanol in the incubation media, the rate of formation of octanoic acid was inhibited by only 30%. The results of these experiments suggest that in the oxidation of octanol to octanoic acid a portion of the octanal formed from octanol is not released from the enzyme but, in the presence of NAD+, is oxidized to octanoic acid.
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PMID:An examination of octanol and octanal metabolism to octanoic acid by horse liver alcohol dehydrogenase. 16 28

An NADPH-dependent aldehyde reductase was purified from rat brain microsomes to electrophoretic homogeneity. The purified enzyme had a molecular weight of 75,000 and reduced long chain fatty aldehydes such as octanal and hexadecanal with higher affinity (Km values of 0.21 mM and 0.03 mM, respectively) than for various artificial carbonyl compounds such as p-nitrobenzaldehyde and p-nitroacetophenone (Km values of 0.31 mM and 1.4 mM, respectively). The purified microsomal aldehyde reductase also showed NADPH-cytochrome c reductase activity, and it could not be distinguished from NADPH-cytochrome c reductase in molecular weight (75,000), chromatographic behavior, electrophoretic mobility, or immunological properties. The solubilized microsomal fraction treated with steapsin lost the reductase activity for hexadecanal but not that for cytochrome c. These results suggest that the aldehyde reductase in brain microsomes is identical to NADPH-cytochrome c reductase and that a hydrophobic portion of the NADPH-cytochrome c reductase is required for the reduction of hexadecanal.
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PMID:Characterization of microsomal NADPH-dependent aldehyde reductase from rat brain. 308 64

The class I (alpha, beta 1, gamma 1, and gamma 2), II (pi), and III (chi) isozymes of human liver alcohol dehydrogenase (ADH) were isolated as electrophoretically homogeneous preparations to examine their kinetics of aldehyde and ketone reduction. While the oxidation of a wide variety of alcohols by ADH has been investigated extensively, the reduction of aldehydes and ketones has received much less attention even though the equilibrium favors the latter process. For each isozyme, the Km and kcat values were measured at pH 7.0 with acetaldehyde, pentanal, octanal, benzaldehyde, and cyclohexanone as substrates. Activity could not be detected with succinic semialdehyde and betaine aldehyde for any of the isozymes. The nonenzymatic hydration, oxidation, and aldol condensation of aldehydes in aqueous solutions present serious experimental obstacles in determining the isozymes' kinetic constants. The effects of these reactions on the enzymatic parameters were studied and compensated for. Michaelis constants for all class I and II isozymes vary by more than 8000-fold, from less than 1 microM for beta 1 gamma 1 and beta 1 beta 1 with octanal to 8.3 mM for pi-ADH for acetaldehyde. However, with any given aldehyde, these values vary by less than 40-fold, and the constants are approximately equal to Km values reported previously for the corresponding alcohols. In contrast, Km values for chi-ADH are extremely high and could be determined accurately only for octanal (75 microM).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Human liver alcohol dehydrogenase isozymes: reduction of aldehydes and ketones. 639 29

A major isozyme of pickerel liver alcohol dehydrogenase has been purified to homogeneity. The enzyme, in addition to catalyze NAD(P)(+)-linked dehydrogenation of alcohols, also mediates dismutation of aldehydes and hydrolysis of esters. Steady-state kinetic studies and chemical modifications of the pickerel liver enzyme with respect to its esterolytic and dismutative activities were carried out. Pickerel liver alcohol dehydrogenase catalyzes hydrolyses of p-nitrophenyl esters via a Uni-Bi mechanism, with alkanoic acids as the last product released. Modifications of Cys and Lys suppress the esterolytic activity. A random mechanism with the formation of dead-end complexes is implicated for the dismutation of octanal catalyzed by pickerel liver alcohol dehydrogenase. Two amino acid residues, Cys and His, are involved in the dehydrogenation as well as dismutation reactions. The present study identifies a regulatory function of Lys for the multifunctional activities of liver alcohol dehydrogenase. When the Lys residue is specifically glucosylated, the dehydrogenase activity increases. Its esterase activity decreases, while the dismutase activity remains unchanged.
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PMID:Multifunctional activities of pickerel liver alcohol dehydrogenase. 819 94

An enzyme isolated from rat liver cytosol (native molecular mass 78. 3 kDa; polypeptide molecular mass 42.5 kDa) is capable of catalysing the NADH/NADPH-dependent degradation of S-nitrosoglutathione (GSNO). The activity utilizes 1 mol of coenzyme per mol of GSNO processed. The isolated enzyme has, as well, several characteristics that are unique to alcohol dehydrogenase (ADH) class III isoenzyme: it is capable of catalysing the NAD+-dependent oxidations of octanol (insensitive to inhibition by 4-methylpyrazole), methylcrotyl alcohol (stimulated by added pentanoate) and 12-hydroxydodecanoic acid, and also the NADH/NADPH-dependent reduction of octanal. Methanol and ethanol oxidation activity is minimal. The enzyme has formaldehyde dehydrogenase activity in that it is capable of catalysing the NAD+/NADP+-dependent oxidation of S-hydroxymethylglutathione. Treatment with the arginine-specific reagent phenylglyoxal prevents the pentanoate stimulation of methylcrotyl alcohol oxidation and markedly diminishes the enzymic activity towards octanol, 12-hydroxydodecanoic acid and S-hydroxymethylglutathione; the capacity to catalyse GSNO degradation is also checked. Additionally, limited peptide sequencing indicates 100% correspondence with known ADH class III isoenzyme sequences. Kinetic studies demonstrate that GSNO is an exceptionally active substrate for this enzyme. S-Nitroso-N-acetylpenicillamine and S-nitrosated human serum albumin are not substrates; the activity towards S-nitrosated glutathione mono- and di-ethyl esters is minimal. Product analysis suggests that glutathione sulphinamide is the major stable product of enzymic GSNO processing, with minor yields of GSSG and NH3; GSH, hydroxylamine, nitrite, nitrate and nitric oxide accumulations are minimal. Inclusion of GSH in the reaction mix decreases the yield of the supposed glutathione sulphinamide in favor of GSSG and hydroxylamine.
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PMID:S-Nitrosoglutathione is a substrate for rat alcohol dehydrogenase class III isoenzyme. 953 10

A previous study of the effect of zinc deprivation on Mycobacterium bovis BCG pointed out the potential importance of an alcohol dehydrogenase for maintaining the hydrophobic character of the cell envelope. In this report, the effect of the overexpression of the M. bovis BCG alcohol dehydrogenase (ADH) in Mycobacterium smegmatis and M. bovis BCG is described. The purification of the enzyme was performed to apparent homogeneity from overexpressing M. bovis BCG cells and its kinetic parameters were determined. The enzyme showed a strong preference for both aromatic and aliphatic aldehydes while the corresponding alcohols were processed 100-1000-fold less efficiently. The best kcat/Km values were found with benzaldehyde > 3-methoxybenzaldehyde > octanal > coniferaldehyde. A phylogenetic analysis clearly revealed that the M. bovis BCG ADH together with the ADHs from Bacillus subtilis and Helicobacter pylori formed a sister group of the class C medium-chain alcohol dehydrogenases, the plant cinnamyl alcohol dehydrogenases (CADs). Comparison of the kinetic properties of our ADH with some related class C enzymes indicated that the mycobacterial enzyme substrate profile resembled that of the CADs involved in plant defence rather than those implicated in lignification. A possible role for the M. bovis BCG ADH in the biosynthesis of the lipids composing the mycobacterial cell envelope is proposed.
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PMID:Overexpression, purification and characterization of Mycobacterium bovis BCG alcohol dehydrogenase. 1033 11

Identification of Solanum tuberosum genes responsive to culture filtrates (CF) from Erwinia carotovora subsp. carotovora led to the isolation of a full-length cDNA with high sequence similarity to several alcohol dehydrogenases. Accumulation of transcripts corresponding to this defence-related alcohol dehydrogenase (drd-1) was rapidly induced in CF-treated and wounded plants. The gene was also responsive to molecules involved in defence signalling such as salicylic acid, methyl jasmonate and ethylene. To elucidate the biochemical function of DRD-1, its cDNA was expressed in Escherichia coli. Enzymatic assays revealed that DRD-1 is an alcohol:NADP+ oxidoreductase with preference for various aromatic and aliphatic aldehydes. The enzyme exhibited high activity with several aldehydes including 2-methoxybenzaldehyde, 3-methoxybenzaldehyde, salicylaldehyde, o-vanillin, cinnamaldehyde, hydrocinnamaldehyde, hexanal and octanal. Identification of the reaction product by thin-layer chromatography confirmed the reduction of aldehydes to alcohols. Enzymatic activity measured with 2-methoxybenzaldehyde as a substrate was increased in salicylic acid- or methyl jasmonate-treated plants. These data suggest that DRD-1 may play an important role in potato defence response to Erwinia carotovora.
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PMID:A novel potato defence-related alcohol:NADP+ oxidoreductase induced in response to Erwinia carotovora. 1282 98

Two alkyl alcohol dehydrogenase (ADH) genes from the long-chain alkane-degrading strain Geobacillus thermodenitrificans NG80-2 were characterized in vitro. ADH1 and ADH2 were prepared heterologously in Escherichia coli as a homooctameric and a homodimeric protein, respectively. Both ADHs can oxidize a broad range of alkyl alcohols up to at least C(30), as well as 1,3-propanediol and acetaldehyde. ADH1 also oxidizes glycerol, and ADH2 oxidizes isopropyl alcohol, isoamylol, acetone, octanal and decanal. The best substrate is ethanol for ADH1 and 1-octanol for ADH2. For both ADHs, the optimum assay condition is at 60 degrees C and pH 8.0, and both NAD and NADP can be used as the cofactor. Sequence analysis reveals that ADH1 and ADH2 belong to the Fe-containing/activated long-chain ADHs. However, the two enzymes contain neither Fe nor other metals, and Fe is not required for the activity, suggesting a new type of ADH. The ADHs characterized here are potentially useful in crude oil bioremediation and other bioconversion processes.
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PMID:Two novel metal-independent long-chain alkyl alcohol dehydrogenases from Geobacillus thermodenitrificans NG80-2. 1938 97

Two cytosolic nicotinamide adenine dinucleotide phosphate-dependent aldehyde reductases, Gox1899 and Gox2253, from Gluconobacter oxydans 621H were overproduced and purified from Escherichia coli. The purified proteins exhibited subunit masses of 26.4 (Gox1899) and 36.7 kDa (Gox2253). Both proteins formed homo-octamers exhibiting native masses of 210 and 280 kDa, respectively. The substrate spectra, optimal reaction conditions, and kinetic constants were determined for Gox1899 and Gox2253. Both enzymes efficiently catalyzed the reduction of medium/long-chain aldehydes. However, Gox1899 had a wider substrate spectrum and was more catalytically efficient. The best activity with Gox1899 was found for aliphatic aldehydes of C6-C10. In contrast, Gox2253 had a limited substrate spectrum and reduced octanal, nonanal, and decanal. Both enzymes were unable to oxidize primary alcohols. Aldehyde removal may be of particular importance for Gluconobacter because the membrane-bound alcohol dehydrogenase rapidly oxidizes short to long-chain alcohols, and large quantities of aldehydes could enter the cell, making detoxification necessary.
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PMID:Analysis of aldehyde reductases from Gluconobacter oxydans 621H. 1964 87