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)

Tritrichomonas foetus mutants resistant to metronidazole lack the hydrogenosomal enzymes pyruvate: ferredoxin oxidoreductase and hydrogenase. Hydrogenosomes of these organisms did not oxidize pyruvate or produce ATP in its presence. Elimination of hydrogenosomal metabolism of pyruvate was compensated by an increased rate of glycolysis. The resistant mutants excreted no organic acids and H2 as metabolic end products. Glycolysis of the resistant T. foetus KV1-1MR-100 can be summarized as 1 mol glucose----2 mol ethanol + 2 mol CO2. The parent strain KV1, excreting H2, CO2 and acidic end products, converted about 10% of glucose to ethanol. Both strains produced ethanol from pyruvate through the action of two cytoplasmic enzymes: pyruvate decarboxylase and alcohol dehydrogenase. The specific activity of the former enzyme, catalyzing nonoxidative decarboxylation of pyruvate to acetaldehyde, was nearly seven times higher in the resistant than in the parent strain. Alcohol dehydrogenase reducing acetaldehyde to ethanol was specific to NADPH; it catalyzed the reverse reaction only slowly, and displayed similar activities in both resistant and sensitive trichomonads. Development of anaerobic metronidazole resistance in T. foetus depended on the loss of pyruvate:ferredoxin oxidoreductase as well as on the ability to increase alcoholic fermentation.
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PMID:Metabolic differences between metronidazole resistant and susceptible strains of Tritrichomonas foetus. 637 46

The metabolism of ethanol to acetate and CO2 by suspension cultures of human blood and marrow cells has been investigated. The average rate of metabolism of ethanol by relatively pure preparations of monocytes plus lymphocytes, neutrophils and erythrocytes obtained from normal peripheral blood were, respectively, 12.58, 5.44 and 0.32 nmol/10(7) cells/h, when the concentration of ethanol in the culture was 2.63 mM. Under similar culture conditions, the average rate of metabolism of ethanol by suspension cultures of human marrow cells was 19.0 nmol/10(7) nucleated marrow cells/h. The metabolism of ethanol by nucleated marrow cells was only slightly inhibited by pyrazole and 3-amino-1,2,4-triazole indicating that it was largely independent of pyrazole-sensitive alcohol dehydrogenase and catalase. By contrast, the oxidation of ethanol by isolated rat hepatocytes was markedly inhibited by pyrazole and therefore appeared to be mainly dependent on alcohol dehydrogenase. It is concluded that bone marrow cells have a considerable capacity to metabolize ethanol and that the predominant biochemical pathway involved in this metabolism is different from that involved in rat hepatocytes.
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PMID:Investigations into the production of acetate from ethanol by human blood and bone marrow cells in vitro. 640 12

We present evidence that cytoplasmic acidosis is a cause of meristematic death in hypoxic root tips of maize and pea seedlings. Usually, leakage of acid from the vacuole is responsible for cytoplasmic acidosis. Leakage of acid, which occurs earlier during hypoxia in pea root tips than in maize root tips, appears to account for the lower tolerance of peas for hypoxia. Cytoplasmic acidosis is accelerated in maize root tips that are either (i) deficient in alcohol dehydrogenase, so that lactic acid production continues throughout hypoxia, or (ii) exposed to external CO2 during hypoxia, or (iii) perfused slowly so that escape of CO2 produced during ethanolic fermentation is retarded. All three conditions decrease the length of time maize root tips can tolerate hypoxia; more rapid cytoplasmic acidosis is associated with more rapid death under hypoxia. Possible mechanisms by which cytoplasmic acidosis leads to death are suggested; the mechanism does not involve inhibition of glycolysis by low pH.
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PMID:Cytoplasmic acidosis as a determinant of flooding intolerance in plants. 659 98

Pentane, a volatile hydrocarbon, is cleared from inspired air by the rat. We have studied this clearance to learn whether or not it is a function of the liver. Rats were put individually into airtight chambers which contained CO2 absorbent and were connected to an O2 reservoir. Pentane was injected into each chamber and chamber atmosphere was assayed frequently for pentane over 6 h by gas chromatography. Semilog plots of pentane concentration had a rapid distribution phase and a log-linear terminal elimination phase. A chamber clearance value in milliliters at atmosphere cleared per minute per kilogram rat weight was calculated. Nephrectomy had no effect on pentane clearance. Liver injury by thioacetamide (5 mmol/kg) or by CCl4 (75 or 125 microliters/100 g) was associated with a marked decrease in pentane clearance, indicating a major role for the liver in pentane elimination. Treatment of rats with inducers or inhibitors of the hepatic microsomal cytochrome P450 system did not affect their ability to clear pentane. However, administration of ethanol or 4-methyl-pyrazole diminished pentane clearance, suggesting that alcohol dehydrogenase may be involved in pentane metabolism. These findings demonstrate that pentane clearance is a liver function.
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PMID:Pentane clearance from inspired air by the rat: dependence on the liver. 684 40

It is well known that the alternations on humoral homeostasis such as a decrease of pH, an elevation of PaCO2 and changes of electrolytes have been detected during respiratory acidosis. The author is of the opinion that the renin-angiotensin-aldosterone system might be related to these changes during respiratory acidosis. Recently, Fujii and Morita have reported that an increase in plasma renin activity appeared during acute respiratory acidosis. These reports prompted me to question whether the renin-angiotensin-aldosterone system was related to the pathophysiological evidence concerning the respiratory acidosis. It is generally accepted that plasma aldosterone concentration is controlled by (1) the renin-angiotensin system, (2) ACTH and (3) serum potassium. Therefore, the purpose of this experiment was to investigate the roles of the renin-angiotensin system and electrolyte metabolism on plasma aldosterone concentration during acute respiratory acidosis. I initiated acute respiratory acidosis with 10% CO2 inhalation in healthy mongrel dogs, and then plasma aldosterone concentration, plasma renin activity, electrolytes and cardiorenal hemodynamics were measured. The results were as follows: 1. The increase of plasma aldosterone concentration was delayed and blurred, in contrast with a significant increase of plasma renin activity, during the acute respiratory acidosis, due to delayed time course of angiotensin II stimulation and also the expected changes in the concentration of angiotensin II receptors on the zona glomerulosa in the adrenal cortex. 2. There was a possibility that the increase in the reabsorption of sodium and water in the proximal tubules, and the increase of ADH secretion during the acute respiratory acidosis, could be related to a decrease in excreted sodium and potassium as well as urine volume. These results suggest that the changes of plasma aldosterone concentration may be affected partially by renin-angiotensin system but not by serum potassium, and plasma aldosterone should be a minimal determinant on the electrolyte metabolism during respiratory acidosis with 10% CO2 inhalation.
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PMID:[The changes on plasma aldosterone concentration during acute respiratory acidosis in dogs. The relationship to renin-angiotensin system and electrolyte metabolism (author's transl)]. 706 60

The physiology of Hanseniaspora uvarum K5 was studied in glucose-limited chemostat cultures and upon glucose pulse. Up to a dilution rate of 0.28 h-1, glucose was completely metabolized in biomass and CO2. Above this value, increase in the dilution rate was accompanied by sequential production of metabolites (glycerol, acetate and ethanol) and decrease in cell yield. Similar results were observed upon glucose pulse. From the enzyme activities (pyruvate dehydrogenase, pyruvate decarboxylase, NAD and NADP-dependent acetaldehyde dehydrogenases, acetyl coenzyme A synthetase and alcohol dehydrogenase) and substrate affinities, the following conclusions were drawn with respect to product formation of cells: (1) pyruvate was preferentially metabolized via pyruvate dehydrogenase, when biomass and CO2 were the only products formed; (2) acetaldehyde formed by pyruvate decarboxylase was preferentially oxidized in acetate by NADP-dependent aldehyde dehydrogenase; acetate accumulation results from insufficient activity of acetyl-CoA synthetase required for the complete oxidation of acetate; (3) acetaldehyde was oxidized in ethanol by alcohol dehydrogenase, in addition to acetate production.
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PMID:Glucose metabolism, enzymic analysis and product formation in chemostat culture of Hanseniaspora uvarum. 778 33

The xylose metabolism of Bacteroides xylanolyticus X5-1 was studied by determining specific enzyme activities in cell free extracts, by following 13C-label distribution patterns in growing cultures and by mass balance calculations. Enzyme activities of the pentose phosphate pathway and the Embden-Meyerhof-Parnas pathway were sufficiently high to account for in vivo xylose fermentation to pyruvate via a combination of these two pathways. Pyruvate was mainly oxidized to acetyl-CoA, CO2 and a reduced cofactor (ferredoxin). Part of the pyruvate was converted to acetyl-CoA and formate by means of a pyruvate-formate lyase. Acetyl-CoA was either converted to acetate by a combined action of phosphotransacetylase and acetate kinase or reduced to ethanol by an acetaldehyde dehydrogenase and an ethanol dehydrogenase. The latter two enzymes displayed both a NADH- and a NADPH-linked activity. Cofactor regeneration proceeded via a reduction of intermediates of the metabolism (i.e. acetyl-CoA and acetaldehyde) and via proton reduction. According to the deduced pathway about 2.5 mol ATP are generated per mol of xylose degraded.
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PMID:D-xylose catabolism in Bacteroides xylanolyticus X5-1. 804 43

The ability of yeast strains to perform both alcoholic and malolactic fermentation in winemaking was studied with a view to achieving a better control of malolactic fermentation in enology. The malolactic gene of Lactococcus lactis (mleS) was expressed in Saccharomyces cerevisiae and Schizosaccharomyces pombe. The heterologous protein is expressed at a high level in cell extracts of a S. cerevisiae strain expressing the gene mleS under the control of the alcohol dehydrogenase (ADH1) promoter on a multicopy plasmid. Malolactic enzyme specific activity is three times higher than in L. lactis extracts. Saccharomyces cerevisiae expressing the malolactic enzyme produces significant amounts of L-lactate during fermentation on glucose-rich medium in the presence of malic acid. Isotopic filiation was used to demonstrate that 75% of the L-lactate produced originates from endogenous L-malate and 25% from exogenous L-malate. Moreover, although a small amount of exogenous L-malate was degraded by S. cerevisiae transformed or not by mleS, all the exogenous degraded L-malate was converted into L-lactate via a malolactic reaction in the recombinant strain, providing evidence for very efficient competition of malolactic enzyme with the endogenous malic acid pathways. These results indicate that the sole limiting step for S. cerevisiae in achieving malolactic fermentation is in malate transport. This was confirmed using a different model, S. pombe, which efficiently degrades L-malate. Total malolactic fermentation was obtained in this strain, with most of the L-malate converted into L-lactate and CO2. Moreover, L-malate was used preferentially by the malolactic enzyme in this strain also.
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PMID:Malolactic fermentation by engineered Saccharomyces cerevisiae as compared with engineered Schizosaccharomyces pombe. 890 33

A stoichiometric model describing the anaerobic metabolism of Saccharomyces cerevisiae during growth on a defined medium was derived. The model was used to calculate intracellular fluxes based on measurements of the uptake of substrates from the medium, the secretion of products from the cells, and of the rate of biomass formation. Furthermore, measurements of the biomass composition and of the activity of key enzymes were used in the calculations. The stoichiometric network consists of 37 pathway reactions involving 43 compounds of which 13 were measured (acetate, CO2, ethanol, glucose, glycerol, NH4+, pyruvate, succinate, carbohydrates, DNA, lipids, proteins and RNA). The model was used to calculate the production rates of malate and fumarate and the ethanol measurement was used to validate the model. All rate measurements were performed on glucose-limited continuous cultures in a high-performance bioreactor. Carbon balances closed within 98%. The calculations comprised flux distributions at specific growth rates of 0.10 and 0.30 h-1. The fluxes through reactions located around important branch points of the metabolism were compared, i.e. the split between the pentose phosphate and the Embden-Meyerhoff-Parnas pathways. Also the model was used to show the probable existence of a redox shunt across the inner mitochondrial membrane consisting of the reactions catalysed by the mitochondrial and the cytosolic alcohol dehydrogenase. Finally it was concluded that cytosolic isocitrate dehydrogenase is probably not present during growth on glucose. The importance of basing the flux analysis on accurate measurements was demonstrated through a sensitivity analysis. It was found that the accuracy of the measurements of CO2, ethanol, glucose, glycerol and protein was critical for the correct calculation of the flux distribution.
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PMID:Flux distributions in anaerobic, glucose-limited continuous cultures of Saccharomyces cerevisiae. 902 95

The sulfate-reducing bacterium Desulfovibrio gigas accumulates large amounts of polyglucose as an endogenous carbon and energy reserve. In the absence of exogenous substrates, the intracellular polysaccharide was utilized, and energy was conserved in the process (H. Santos, P. Fareleira, A. V. Xavier, L. Chen, M.-Y. Liu, and J. LeGall, Biochem. Biophys. Res. Commun. 195:551-557, 1993). When an external electron acceptor was not provided, degradation of polyglucose by cell suspensions of D. gigas yielded acetate, glycerol, hydrogen, and ethanol. A detailed investigation of the metabolic pathways involved in the formation of these end products was carried out, based on measurements of the activities of glycolytic enzymes in cell extracts, by either spectrophotometric or nuclear magnetic resonance (NMR) assays. All of the enzyme activities associated with the glycogen cleavage and the Embden-Meyerhof pathway were determined as well as those involved in the formation of glycerol from dihydroxyacetone phosphate (glycerol-3-phosphate dehydrogenase and glycerol phosphatase) and the enzymes that catalyze the reactions leading to the production of ethanol (pyruvate decarboxylase and ethanol dehydrogenase). The key enzymes of the Entner-Doudoroff pathway were not detected. The methylglyoxal bypass was identified as a second glycolytic branch operating simultaneously with the Embden-Meyerhof pathway. The relative contribution of these two pathways for polyglucose degradation was 2:3. 13C-labeling experiments with cell extracts using isotopically enriched glucose and 13C-NMR analysis supported the proposed pathways. The information on the metabolic pathways involved in polyglucose catabolism combined with analyses of the end products formed from polyglucose under fermentative conditions provided some insight into the role of NADH in D. gigas. In the presence of electron acceptors, NADH resulting from polyglucose degradation was utilized for the reduction of sulfate, thiosulfate, or nitrite, leading to the formation of acetate as the only carbon end product besides CO2. Evidence supporting the role of NADH as a source of reducing equivalents for the production of hydrogen is also presented.
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PMID:Pathways for utilization of carbon reserves in Desulfovibrio gigas under fermentative and respiratory conditions. 919 Aug 14


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