scholarly journals The activation of aldehyde dehydrogenase by diethylstilboestrol and 2,2′-dithiodipyridine

1982 ◽  
Vol 207 (1) ◽  
pp. 81-89 ◽  
Author(s):  
T M Kitson
Keyword(s):  
Enzyme Activity ◽  
Aldehyde Dehydrogenase ◽  
Human Liver ◽  
Common Property ◽  
Rabbit Liver ◽  
Aldehyde Dehydrogenases ◽  
Cytoplasmic Enzyme ◽  
Sheep Liver ◽  
Low Concentrations ◽  
Liver Aldehyde Dehydrogenase

1. The activation of sheep liver cytoplasmic aldehyde dehydrogenase by diethylstilboestrol and by 2,2′-dithiodipyridine is described. The effects of the two modifiers are very similar with respect to variation with acetaldehyde concentration, pH and temperature. Thus the degree of activation is maximal when the enzyme is assayed at approx. 1 mM-acetaldehyde, is greater at 25 degrees C than at 37 degrees C, and is greater at pH 7.4 than at pH 9.75. With low concentrations of acetaldehyde both modifiers decrease the enzyme activity. 2. Diethylstilboestrol affects the sheep liver cytoplasmic enzyme in a very similar way to that previously described for a rabbit liver cytoplasmic enzyme. Preliminary experiments show that the same is true for a preparation of human liver aldehyde dehydrogenase. It is proposed that sensitivity to diethylstilboestrol (and steroids) is a common property of all mammalian cytoplasmic aldehyde dehydrogenases.

Human liver aldehyde dehydrogenase: partial purification and properties

1969 ◽  
Vol 47 (3) ◽  
pp. 265-272 ◽  
Author(s):  
A. H. Blair ◽  
F. H. Bodley
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Human Liver ◽  
Deae Cellulose ◽  
Maximal Activity ◽  
Partial Purification ◽  
Aliphatic Aldehydes ◽  
Low Concentrations ◽  
Purification And Properties ◽  
Liver Aldehyde Dehydrogenase ◽  
Metabolic Reduction

Aldehyde dehydrogenase was partially purified from human liver. During purification, activity was resolved into one major and one minor species by DEAE-cellulose column chromatography; the properties of the predominant form were investigated.Aldehydes are oxidized when NAD+, but not NADP+, is the electron acceptor, maximal activity occurring between pH 9 and 10. Several aliphatic aldehydes and hydroxyaldehydes served as substrates for the enzyme. Benzaldehyde also was oxidized, but at a comparatively low rate. Aliphatic aldehydes carrying negatively charged groups are not oxidized. The enzyme is sensitive to low concentrations of two sulfhydryl reagents, p-chloromercuribenzoate and mercuric ions; this inhibition was reversed with sulfhydryl compounds. Like other aldehyde dehydrogenases, the human liver enzyme is inhibited by arsenite and the inhibition is potentiated by mercaptoethanol. Only 35% inhibition was produced by disulfiram at 40 μM; and diethyldithiocarbamate, its metabolic reduction product, had no effect on activity below 10 mM.

scholarly journals The separation of sheep liver cytoplasmic and mitochondrial aldehyde dehydrogenases by isoelectric focusing, and observations on the purity of preparations of the cytoplasmic enzyme, and their sensitivity towards inhibition by disulfiram

1979 ◽  
Vol 179 (3) ◽  
pp. 709-712 ◽  
Author(s):  
F M Dickinson ◽  
S Berrieman
Keyword(s):  
Isoelectric Focusing ◽  
Aldehyde Dehydrogenase ◽  
Liver Enzymes ◽  
Mitochondrial Enzyme ◽  
Selective Precipitation ◽  
Aldehyde Dehydrogenases ◽  
Cytoplasmic Enzyme ◽  
Sheep Liver ◽  
Ph Range

Preparations of sheep liver cytoplasmic aldehyde dehydrogenase obtained by published methods were found by analytical isoelectric focusing in the pH range 5–8 to contain 5–10% by weight of the mitochondrial aldehyde dehydrogenase. Under the conditions used the pI of the cytoplasmic enzyme is 6.2 and that of the mitochondrial enzyme 6.6. The mitochondrial enzyme can be removed from the preparation by selective precipitation of the cytoplasmic enzyme with (NH4)2SO4. Kinetic experiments and inhibition experiments with disulfiram show that the properties of the two sheep liver enzymes are so different that the presence of 10% mitochondrial enzyme in preparations of the cytoplasmic enzyme can introduce serious errors into results. Our results suggest that the presence of 10 microM-disulfiram in assays may completely inactivate the pure cytoplasmic enzyme. This result is in contrast with a previous report [kitson (1978) Biochem. U. 175, 83–90].

scholarly journals Aldehyde dehydrogenase in 2-acetaminofluorene-induced rat hepatomas. Ontogeny and evidence that the new isoenzymes are not due to normal gene de-repression

1977 ◽  
Vol 164 (1) ◽  
pp. 119-123 ◽  
Author(s):  
Ronald Lindahl
Keyword(s):  
Rat Liver ◽  
Aldehyde Dehydrogenase ◽  
Double Diffusion ◽  
Normal Liver ◽  
Normal Adult ◽  
Sprague Dawley ◽  
Adult Liver ◽  
Aldehyde Dehydrogenases ◽  
Adult Rat ◽  
Liver Aldehyde Dehydrogenase

The pre- and post-natal ontogeny of Sprague–Dawley rat liver aldehyde dehydrogenase [aldehyde–NAD(P)+ oxidoreductase, EC 1.2.1.5] is described. At no time in its ontogenetic development does normal liver aldehyde dehydrogenase exhibit any of the characteristics of a series of unique aldehyde dehydrogenases that can be isolated from 2-acetamidofluorene-induced rat hepatomas. Enzyme activity is first detectable in 15-day foetal liver and gradually increases throughout pre- and post-natal development until adult activities are attained by day 49 after birth. Electrophoretically, normal aldehyde dehydrogenase, throughout its ontogeny, exists as the same single isoenzyme found in normal adult liver. Isoelectric points for two normal liver isoenzymes demonstrable by isoelectric focusing are pH5.9 and 6.0. The immunochemical properties of aldehyde dehydrogenase during its ontogeny are identical with those of normal adult liver aldehyde dehydrogenase when tested against anti-(hepatoma aldehyde dehydrogenase) serum in Ouchterlony double-diffusion tests. The results indicate that the hepatoma-specific aldehyde dehydrogenases are not the result of the de-repression of genes normally repressed in adult rat liver or in some other adult tissue.

scholarly journals Reaction between sheep liver mitochondrial aldehyde dehydrogenase and various thiol-modifying reagents

1989 ◽  
Vol 261 (1) ◽  
pp. 281-284 ◽  
Author(s):  
K M Loomes ◽  
T M Kitson
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Related Compound ◽  
Physiological Responses ◽  
Enzymic Activity ◽  
Cysteine Residues ◽  
Mitochondrial Enzyme ◽  
Step Process ◽  
Cytoplasmic Enzyme ◽  
Sheep Liver

Sheep liver mitochondrial aldehyde dehydrogenase reacts with 2,2′-dithiodipyridine and 4,4′-dithiodipyridine in a two-step process: an initial rapid labelling reaction is followed by slow displacement of the thiopyridone moiety. With the 4,4′-isomer the first step results in an activated form of the enzyme, which then loses activity simultaneously with loss of the label (as has been shown to occur with the cytoplasmic enzyme). With 2,2′-dithiodipyridine, however, neither of the two steps of the reaction has any effect on the enzymic activity, showing that the mitochondrial enzyme possesses two cysteine residues that must be more accessible or reactive (to this reagent at least) than the postulated catalytically essential residue. The symmetrical reagent 5,5′-dithiobis-(1-methyltetrazole) activates mitochondrial aldehyde dehydrogenase approximately 4-fold, whereas the smaller related compound methyl l-methyltetrazol-5-yl disulphide is a potent inactivator. These results support the involvement of mixed methyl disulphides in causing unpleasant physiological responses to ethanol after the ingestion of certain antibiotics.

scholarly journals Partial reversal of the acetaldehyde and butyraldehyde oxidation reactions catalysed by aldehyde dehydrogenases from sheep liver

1978 ◽  
Vol 175 (2) ◽  
pp. 753-756 ◽  
Author(s):  
G J Hart ◽  
F M Dickinson
Keyword(s):  
Acetic Anhydride ◽  
Mitochondrial Enzyme ◽  
Oxidation Reactions ◽  
Aldehyde Dehydrogenases ◽  
Cytoplasmic Enzyme ◽  
Sheep Liver ◽  
Michaelis Constants ◽  
Butyric Anhydride ◽  
Partial Reversal

In the presence of acetic anhydride or butyric anhydride, liver aldehyde dehydrogenases catalyse the oxidation of NADH at pH 7.0 and 25 degrees C. The maximum velocities and Michaelis constants for NADH at saturating anhydride concentrations are independent of which anhydride is used, the values being V′max. = 12 min-1 and Km for NADH = 9 micrometer for the mitochondrial enzyme and V′max = 25 min-1 and Km for NADH = 20 micrometer for the cytoplasmic enzyme. Substitution of [4A-2H]NADH for NADH resulted in 2-fold and 4-fold decreases in rate for the mitochondrial and cytoplasmic enzymes respectively.

scholarly journals Steady-state and pre-steady kinetic studies on mitochondrial sheep liver aldehyde dehydrogenase. A comparison with the cytoplasmic enzyme

1978 ◽  
Vol 171 (3) ◽  
pp. 527-531 ◽  
Author(s):  
A K H MacGibbon ◽  
L F Blackwell ◽  
P D Buckley
Keyword(s):  
Steady State ◽  
Aldehyde Dehydrogenase ◽  
Kinetic Studies ◽  
Kinetic Properties ◽  
Protein Fluorescence ◽  
Sheep Liver ◽  
Steady State Kinetic ◽  
Wide Range ◽  
Liver Aldehyde Dehydrogenase

Kinetic studies were carried out on mitochondrial aldehyde dehydrogenase (EC 1.2.1.3) isolated from sheep liver. Steady-state studies over a wide range of acetaldehyde concentrations gave a non-linear double-reciprocal plot. The dissociation of NADH from the enzyme was a biphasic process with decay constants 0.6s-1 and 0.09s-1. Pre-steady-state kinetic data with propionaldehyde as substrate could be fitted by using the same burst rate constant (12 +/- 3s-1) over a wide range of propionaldehyde concentrations. The quenching of protein fluorescence on the binding of NAD+ to the enzyme was used to estimate apparent rate constants for binding (2 × 10(4) litre.mol-1.s-1) and dissociation (4s-1). The kinetic properties of the mitochondrial enzyme, compared with those reported for the cytoplasmic aldehyde dehydrogenase from sheep liver, show significant differences, which may be important in the oxidation of aldehydes in vivo.

Spatial distribution of human liver aldehyde dehydrogenase isoenzymes

1999 ◽  
Vol 111 (6) ◽  
pp. 461-466 ◽  
Author(s):  
I. Piotr Maly ◽  
Valérie Crotet ◽  
D. Sasse
Keyword(s):  
Spatial Distribution ◽  
Aldehyde Dehydrogenase ◽  
Human Liver ◽  
Liver Aldehyde Dehydrogenase
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