Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.2.13 (aldolase)
 3,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

After a brief exposition to glucose, Thiobacillus acidophilus was isolated from a culture of iron-grown T. ferrooxidans. Physicochemical analysis of its DNA showed a G+C content of 62.9-63.2%. The new isolate grows best at 25-30 degrees C and at pH 3.0. Growth is possible between pH 1.5 and 6.0. Thiobacillus acidophilus is apparently strictly aerobic. Ammonium salts are the only suitable source of nitrogen. The bacterium is a facultative autotroph. In addition to elemental sulfur, it obtains energy from organic compounds such as D-glucose, D-galactose, D-fructose, D-mannitol, D-xylose, D-ribose, D-arabinose, L-arabinose, sucrose, sodium citrate, malic acid,dl-aspartic acid, and dl-glutamic acid. Thiobacillus acidophilus possesses the key enzymes of the tricarboxylic acid (TCA) cycle including NAD-and NADP-linked isocitric dehydrogenase and alpha-ketoglutarate dehydrogenase, and the key enzymes of the hexose monophosphate pathway (glucose-6-phosphate and 6-phosphogluconate dehydrogenase, and fructose 1,6-diphosphate aldolase). NADH oxidase has been found in particulate fraction of extracts. Rhodanese and thiosulfate oxidase have also been detected.
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PMID:Thiobacillus acidophilus sp. nov.; isolation and some physiological characteristics. 23 84

A mutant of Rhizobium meliloti selected as unable to grow on L-arabinose also failed to grow on acetate or pyruvate. It grew, but slower than the parental strain, on many other carbon sources. Assay showed it to lack alpha-ketoglutarate dehydrogenase (kgd) activity, and revertants of normal growth phenotype contained the activity again. Other enzymes of the tricarboxylic acid cycle and of the glyoxylate cycle were present in both mutant and parent strains. Enzymes of pyruvate metabolism were also assayed. L-Arabinose degradation in R. meliloti was found to differ from the known pathway in R. japonicum, since the former strain lacked 2-keto-o-deoxy-L-arabonate aldolase but contained alpha-ketoglutarate semialdehyde dehydrogenase; thus, it is likely that R. meliloti has the L-arabinose pathway leading to alpha-ketoglutarate rather than the one to glycolaldehyde and pyruvate. This finding accounts for the L-arabinose negativity of the mutant. Resting cells of the mutant were able to metabolize the three substrates which did not allow growth.
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PMID:alpha-Ketoglutarate dehydrogenase mutant of Rhizobium meliloti. 76 18

Crude extracts of both vegetative cells and glycerol-induced microcysts of Myxococcus xanthus contained the following enzyme activities: phosphofructokinase, phosphoglucoisomerase, fructose-1,6-diphosphatase, fructosediphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate carboxylase, citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and uridine diphosphate glucose pyrophosphorylase. With the exception of isocitrate dehydrogenase, which was present at a fivefold higher concentration in microcysts, all activities in extracts from both types of cells were essentially equal. Hexokinase and pyruvate kinase could not be detected in extracts from either type of cell. Microcysts metabolized acetate at a lower rate than did vegetative cells. Most of this decrease was reflected in a substantial decrease in ability of microcysts to oxidize acetate to CO(2). In addition, microcysts and vegetative cells showed a different distribution of (14)C-label from incorporated acetate.
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PMID:Comparative intermediary metabolism of vegetative cells and microcysts of Myxococcus xanthus. 430 96

By using the continuous culture technique, the transition from aerobiosis to anaerobiosis and its effect on a number of enzymes has been investigated in Escherichia coli K-12. A decrease in the oxygen partial pressure below 28.0 mm of Hg resulted firstly in an increase of the respiratory enzymes (reduced nicotinamide adenine dinucleotide [NADH] oxidase, 2.53-fold; succinic dehydrogenase, 1.4-fold; cytochrome b(1), 3.91-fold; and cytochrome a(2), 2.45-fold) before the electron transport system gradually collapsed as cytochrome a(2), followed by cytochrome b(1), succinic dehydrogenase, and finally NADH oxidase decreased in activity. The change from respiration to fermentation was initiated well before the oxygen tension reached zero by the increase in levels of fructose diphosphate-aldolase, glucose 6-phosphate, and 6-phosphogluconate dehydrogenases and a decrease in 2-oxoglutarate dehydrogenase. Whem the dissolved oxygen tension reached zero, dry weight and CO(2) formation together with isocitrate dehydrogenase decreased, whereas acid production and phosphofructokinase synthesis started to increase. Enzymatic investigations revealed that the kinetics of the enzyme phosphofructokinase from strict aerobic cultures (6.9 ppm oxygen in solution) was adenosine triphosphate (ATP)-insensitive, whereas the same enzyme from anaerobic cultures was ATP-sensitive. A mechanism is proposed for the change from aerobiosis to anaerobiosis together with the occurring change in glucose regulation.
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PMID:Effect of oxygen on several enzymes involved in the aerobic and anaerobic utilization of glucose in Escherichia coli. 434 16

Glucose-6-phosphate dehydrogenase and the enzymes of the Entner-Doudoroff pathway, 6-phosphogluconate dehydrase and 2-keto-3-deoxy-6-phosphogluconate aldolase (assayed together), are induced during heterotrophic growth of Thiobacillus ferrooxidans on an iron-glucose-supplemented medium or on glucose alone. By contrast, autotrophic cells (iron-grown) contain low levels of these enzymes. Fructose 1, 6-diphosphate aldolase, an enzyme of the Embden-Meyerhof pathway, is present at low levels irrespective of the growth medium, suggesting that this enzyme is not involved in energy-yielding reactions but merely provides intermediates for biosynthesis. The Entner-Doudoroff and pentose-phosphate pathways are the principle means through which glucose is dissimilated and is presumed to be concerned with energy production. Isotopic studies showed that a high rate of CO(2) formation from specifically labeled glucose came from carbon atoms 1 and 4. An unexpectedly high rate of evolution of CO(2) also came from carbon 6, suggesting that the triose phosphate formed during glucose breakdown and specifically as a result of 2-keto-3-deoxy-6-phosphogluconate aldolase activity, was metabolized via some unorthodox metabolic route. Cells grown in the iron-supplemented and glucose-salts media have a complete tricarboxylic acid cycle, whereas autotrophically grown T. ferrooxidans lacked both alpha-ketoglutarate dehydrogenase and reduced nicotinamide adenine dinucleotide oxidase. Two isocitrate dehydrogenases [nicotinamide adenine dinucleotide (NAD) and NAD phosphate (NADP) specific] were present. NAD-linked enzyme was constitutive, whereas the NADP-linked enzyme was induced upon adaptation of autotrophic cells to heterotrophic growth.
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PMID:Heterotrophic metabolism of the chemolithotroph Thiobacillus ferrooxidans. 439 39

The alpha-ketoglutarate dehydrogenase complex of either pig heart or Escherichia coli catalyzes a NAD- and CoASH-dependent oxidation of 2-keto-4-hydroxyglutarate which is stereoselective toward the L-isomer of this hydroxyketo acid. L-Malyl-CoA is the product of the reaction; the evidence includes observing (a) a steady increase in absorbance at 230 nm during the oxidation of 2-keto-4-hydroxyglutarate, (b) a positive response of oxidation reaction mixtures to neutral hydroxylamine, (c) loss of the two foregoing results concomitant with release of thiol-reacting material and the formation of free malate when reaction mixtures are heated, (d) formation of a hydroxamate which has chromatographic mobilities identical to that of chemically synthesized malate hydroxamate, (e) enzymatic formation of a radioactive product from 14C-labeled 2-keto-4-hydroxyglutarate which co-migrates with chemically synthesized malyl-CoA, and (f) hydrolysis of the product by citrate synthase, an enzyme absolutely specific for citryl-CoA and L-malyl-CoA. A 1:1:1 stoichiometric relationship exists between the amount of 2-keto-4-hydroxyglutarate oxidized, NAD reduced, and malate (or malyl-CoA) formed. Results from studies in which either 14C-labeled 2-keto-4-hydroxyglutarate, pyruvate, or glyoxylate is incubated with mixtures of purified enzymes or extracts of E. coli support the suggestion that the aldolase which preferentially catalyzes formation of L-2-keto-4-hydroxyglutarate from pyruvate plus glyoxylate in E. coli is coupled with the oxidative decarboxylation of this substrate, as reported here, and other enzymes in a multistep pyruvate-catalyzed cyclic oxidation of glyoxylate.
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PMID:Malyl-CoA formation in the NAD-, CoASH-, and alpha-ketoglutarate dehydrogenase-dependent oxidation of 2-keto-4-hydroxyglutarate. Possible coupled role of this reaction with 2-keto-4-hydroxyglutarate aldolase activity in a pyruvate-catalyzed cyclic oxidation of glyoxylate. 638 79

1. With fumarate as the terminal electron acceptor and either H2 or formate as donor, Vibrio succinogenes could grow anaerobically in a mineral medium using fumarate as the sole carbon source. Both the growth rate and the cell yield were increased when glutamate was also present in the medium. 2. Glutamate was incorporated only into the amino acids of the glutamate family (glutamate, glutamine, proline and arginine) of the protein. The residual cell constituents were synthesized from fumarate. 3. Pyruvate and phosphoenolpyruvate, as the central intermediates of most of the cell constituents, were formed through the action of malic enzyme and phosphoenolpyruvate synthetase. Fructose-1,6-bisphosphate aldolase was present in the bacterium suggesting that this enzyme is involved in carbohydrate synthesis. 4. In the absence of added glutamate the amino acids of the glutamate family were synthesized from fumarate via citrate. The enzymes involved in glutamate synthesis were present. 5. During growth in the presence of glutamate, net reducing equivalents were needed for cell synthesis. Glutamate and not H2 or formate was used as the source of these reducing equivalents. For this purpose part of the glutamate was oxidized to yield succinate and CO2. 6. The alpha-ketoglutarate dehydrogenase involved in this reaction was found to use ferredoxin as the electron acceptor. The ferredoxin of the bacterium was reoxidized by means of a NADP-ferredoxin oxidoreductase. Enzymes catalyzing the reduction of NAD, NADP or ferredoxin by H2 or formate were not detected in the bacterium.
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PMID:Biosynthetic Pathways of Vibrio succinogenes growing with fumarate as terminal electron acceptor and sole carbon source. 710 60

A method was developed to measure the activities of enzymes in extracts from single human preimplantation embryos. The method permits the analysis of two enzymes plus appropriate controls in an extract from a single embryo, and was used to investigate the control of energy metabolism during the development of human embryos from the two-cell to the blastocyst stage. Hexokinase (HK), 6-phosphofructokinase (PFK), pyruvate kinase (PK), fructose-1,6-diphosphate aldolase (ALD), glucose phosphate isomerase (GPI), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PDH) and 2-oxoglutarate dehydrogenase (ODH) were all detectable, whereas glycogen phosphorylase (GP) was not. The enzyme activities of ODH, PFK, LDH, PK, GPI and G6PDH, averaged over all stages of development from the two-cell to blastocyst stage (days 2-6 after insemination), were 3.5, 6.6, 15, 69, 73 and 87 times greater than HK, respectively. The activity of ALD was very similar to that of HK. The activities of ALD, GPI, PFK, PK and LDH showed no significant variation with stage of development, although the activity of GPI fell significantly from the four-eight cell to the eight-sixteen cell stage (P < 0.05). HK activity decreased from the two-eight cell to the eight-sixteen cell (P < 0.05), and increased significantly from the eight-sixteen cell to the blastocyst stage (P < 0.01). The overall relationship between hexokinase activity and stage approached significance (P = 0.059, one-way analysis of variance). The activity of G6PDH decreased significantly with development (P < 0.001, one way analysis of variance).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Activity of enzymes of energy metabolism in single human preimplantation embryos. 828 48

We evaluated the effect of sodium molybdate on carbohydrate metabolizing enzymes and mitochondrial enzymes in diabetic rats. Diabetic rats showed a significant reduction in the activities of glucose metabolising enzymes like hexokinase, glucose-6-phosphate dehydrogenase, glycogen synthase and in the level of glycogen. An elevation in the activities of aldolase, glucose-6-phosphatase, fructose 1,6- bisphosphatase, glycogen phosphorylase and in the level of blood glucose were also observed in diabetic rats when compared to control rats. The activities of mitochondrial enzymes isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH-dehydrogenase and cytochrome-C-oxidase were also significantly lowered in diabetic rats. Molybdate administration to diabetic rats reversed the above changes in a significant manner. From our observations, we conclude that administration of sodium molybdate regulated the blood sugar levels in alloxan-induced diabetic rats. Sodium molybdate therapy not only maintained the blood glucose homeostasis but also altered the activities of carbohydrate metabolising enzymes. Molybdate therapy also considerably improved the activities of mitochondrial enzymes, thereby suggesting its role in mitochondrial energy production.
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PMID:Effect of sodium molybdate on carbohydrate metabolizing enzymes in alloxan-induced diabetic rats. 1183 16

Semecarpus anacardium Linn. of the family Anacardiaceae has many applications in the Ayurvedic and Siddha systems of medicine. We have evaluated the effect of S. anacardium nut milk extract on carbohydrate metabolizing enzymes and mitochondrial tricarboxylic acid cycle and respiratory enzymes in liver and kidney mitochondria of dimethyl benzanthracene-induced mammary carcinoma in Sprague-Dawley rats. Mammary carcinoma-bearing rats showed a significant rise in glycolytic enzymes (hexokinase, phosphoglucoisomerase and aldolase) and a simultaneous fall in gluconeogenic enzymes (glucose-6-phosphatase and fructose 1,6-diphosphatase). The activities of mitochondrial enzymes isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, NADH-dehydrogenase and cytochrome C oxidase were significantly lowered in mammary carcinoma-bearing rats when compared with control rats. S. anacardium nut extract administration to tumour-induced animals significantly lowered the glycolytic enzyme activities (hexokinase, phosphoglucoisomerase and aldolase) and there was a rise in gluconeogenic enzymes (glucose-6-phosphatase and fructose 1,6-diphosphatase), which indicated an antitumour and anticancer effect. Comparison of normal control rats and rats administered S. anacardium only as drug control animals showed no significant variations in enzyme activities. S. anacardium nut extract administration to dimethyl benzanthracene-tumour-induced animals significantly increased the activities of mitochondrial enzymes, thereby suggesting its role in mitochondrial energy production.
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PMID:Therapeutic effect of Semecarpus anacardium Linn. nut milk extract on carbohydrate metabolizing and mitochondrial TCA cycle and respiratory chain enzymes in mammary carcinoma rats. 1460 72


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