[78] Liver alcohol dehydrogenase

Bonnichsen, Roger; Brink, Norman G.

doi:10.1016/0076-6879(55)01083-5

Cited by 163 publications

(48 citation statements)

References 5 publications

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“…for 30 mins at 4°C, and ADH activity in the supernatant estimated essentially according to the method of Bonnichsen and Brink (1955). Change in absorbance at 340 nm, due to the reduction of NAD, was recorded over two minutes at 23°C.…”

Section: Methodsmentioning

confidence: 99%

A mutational analysis of the alcohol dehydrogenase system in barley

Harberd

Edwards

1982

Heredity

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SUMMARYEvidence that the alcohol dehydrogenase enzymes in barley are specified by two genes, Adh 1 and Adh 2 whose products (ADH1 and ADH2) associate by dimerization to give three isozyme sets, Set I (ADH1 . ADHI homodimer), Set II (ADH1 . ADH2 heterodimer) and Set III (ADH2 . ADH2 homodimer) is presented. Procedures for the induction and recovery of null activity mutants at the Adh 1 locus are described. One such mutant, Adh 1 -M9, when homozygous results in the absence of Set I and Set H isozymes and in a decrease in the rate of induction of alcohol dehydrogenase activity caused by flooding.

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Section: Methodsmentioning

confidence: 99%

A mutational analysis of the alcohol dehydrogenase system in barley

Harberd

Edwards

1982

Heredity

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“…Malate dehydrogenase [32], lactate dehydrogenase [33] and glutamate dehydrogenase [34] were assayed by measuring the rate of decrease in absorbance of NADH at 25 "C. Glyceraldehyde-3-phosphate dehydrogenase was assayed by measuring the coupled reaction with phosphoglycerate kinase 1351. Alcohol dehydrogenase was assayed by measuring the rate of increase in absorbance of NADH at 25 "C [36].…”

Section: Preparation and Assay O J Substrate Enzymesmentioning

confidence: 99%

Crystallization and Properties of Cathepsin B from Rat Liver

1979

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Cathepsin B from rat liver was purified to apparent homogeneity by cell-fractionation, freezing and thawing, acetone treatment, gel filtration, DEAE-Sephadex and CM-Sephadex column chromatography, and was crystallized. The purified enzyme formed spindle-shaped crystals and its homogeneity was proved by disc gel electrophoresis in the presence of sodium dodecyl sulfate and by ultracentrifugical analysis.Its ~2 0 ,~ value was 2.8 S and its relative molecular mass was calculated to be 22 500 (k 900) by sedimentation equilibrium analysis. Crystalline cathepsin B was shown to consist of four isozymes with isoelectric points between pH 4.9 and 5.3, the main isozyme having an isoelectric point of pH 5.0. The enzyme was irreversibly inactivated by exposure to weak alkali. The pH optimum was 6.0 with a-N-benzoyl-~~-arginine-4-nitroanilide as substrate. Amino acid analysis showed that the enzyme contained hexosamine, glucosamine and galactosamine. Cathepsin B inactivated aldolase, glucokinase, apo-ornithine aminotransferase, and apo-cystathionase, but the rates of inactivation of glucokinase, apo-ornithine aminotransferase, and apocystathionase were lower than that of aldolase. Studies by polyacrylamide gel electrophoresis in the presence and absence of sodium dodecyl sulfate showed that cathepsin B degraded apo-ornithine aminotransferase to two polypeptide chains differing in relative molecular mass and electrophoretic mobility.Inhibitors of so-called cathepsin B reduce protein degradation in various experimental systems. This has been demonstrated with leupeptin in a system in vitro [l] and in tissue culture [2] and with chloroquine in tissue culture [3]. Therefore, it is thought that cathepsin B is important in intracellular protein degradation. Cathepsin B has been found in various mammalian tissues and its purification has been attempted by many workers. The preparation of cathepsin B of Greenbaum and Fruton [4] was demonstrated by Otto

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“…Homogenates of liver (10%, w/v) in 0.25 M-sucrose containing 1% Triton X-100 (Raiha & Koskinen, 1964) were centrifuged at 5000g for 30min and the supernatants were used for the determination of alcohol dehydrogenase activity as described by Bonnischsen & Brink (1955).…”

Section: Alcohol Dehydrogenase Activitymentioning

confidence: 99%

Metabolic alterations produced in the liver by chronic ethanol administration. Increased oxidative capacity

Videla

Bernstein

Israel

1973

Biochemical Journal

180

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1. Administration of ethanol (14g/day per kg) for 21-26 days to rats increases the ability of the animals to metabolize ethanol, without concomitant changes in the activities of liver alcohol dehydrogenase or catalase. 2. Liver slices from rats chronically treated with ethanol showed a significant increase (40-60%/) in the rate of 02 consumption over that of slices from control animals. The effect of uncoupling agents such as dinitrophenol and arsenate was completely lost after chronic treatment with ethanol. 3. Isolated mitochondria prepared from animals chronically treated with ethanol showed no changes in state 3 or state 4 respiration, ADP/O ratio, respiratory control ratio or in the dinitrophenol effect when succinate was used as substrate. With f-hydroxybutyrate as substrate a small but statistically significant decrease was found in the ADP/O ratio but not in the other parameters or in the dinitrophenol effect. Further, no changes in mitochondrial Mg2+-activated adenosine triphosphatase, dinitrophenol-activated adenosine triphosphatase or in the dinitrophenol-activated adenosine triphosphatase/Mg2+-activated adenosine triphosphatase ratio were found as a result of the chronic ethanol treatment. 4. Liver microsomal NADPH oxidase activity, a H202-producing system, was increased by 80-100 % by chronic ethanol treatment. Oxidation offormate to CO2 in vivo was also increased in these animals. The increase in formate metabolism could theoretically be accounted for by an increased production of H202 by the NADPH oxidase system plus formate peroxidation by catalase. However, an increased production of H202 and oxidation of ethanol by the catalase system could not account for more than 10-20% of the increased ethanol metabolism in the animals chronically treated with ethanol. 5. Results presented indicate that chronic ethanol ingestion results in a faster mitochondrial 02 consumption in situ suggesting a faster NADH reoxidation. Although only a minor change in mitochondrial coupling was observed with isolated mitochondria, the possibility of an uncoupling in the intact cell cannot be completely discarded. Regardless of the mechanism, these changes could lead to an increased metabolism of ethanol and of other endogenous substrates.Previous studies by our group (Videla & Israel, 1970) indicate that the rate of ethanol metabolism by the liver depends on the rate of mitochondrial reoxidation of the cytoplasmic NADH produced in the oxidation of ethanol. Uncoupling agents such as 2,4-dinitrophenol or arsenate were shown to increase markedly the rate of ethanol metabolism by normal rat liver slices. Dinitrophenol was also shown to be effective in increasing the rate of ethanol metabolism in vivo . However, although dinitrophenol increased the ethanol metabolism in liver slices from control animals, it was not effective in those from animals chronically treated with ethanol, in which the rate of ethanol metabolism had already been increased. This suggested that the rate ofethanol metabolism in these animals was no longer ...

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[78] Liver alcohol dehydrogenase

Cited by 163 publications

References 5 publications

A mutational analysis of the alcohol dehydrogenase system in barley

A mutational analysis of the alcohol dehydrogenase system in barley

Crystallization and Properties of Cathepsin B from Rat Liver

Metabolic alterations produced in the liver by chronic ethanol administration. Increased oxidative capacity

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