Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

The enzyme pattern of Saccharomyces cerevisiae was followed during batch growth and in continuous culture in a synthetic medium limited for glucose under aerobic conditions. Seven enzymes were measured: succinate-cytochrome c oxidoreductase, malate dehydrogenase, nicotinamide adenine dinucleotide-linked glutamate dehydrogenase, malate synthase, isocitrate lyase, aldolase, and nicotinamide adenine dinucleotide phosphate (NADP(+))-linked glutamate dehydrogenase. During fermentation of glucose and high growth rate (mu) during the first log phase in batch experiments, the first five enzymes (group I) were repressed, and aldolase and NADP(+)-linked glutamate dehydrogenase (group II) were derepressed. During growth on the accumulated ethyl alcohol and lower mu, the group I enzymes were preferentially formed and the other two were repressed. A sequence of derepression of the group I enzymes was found during the shift from glucose to ethyl alcohol metabolism, which can be correlated with a strong increase in the percentage of single (nonbudding) cells in the population. A correlation between the state of cells in the budding cycle and enzyme repression and derepression is suggested. In continuous culture, the enzyme pattern was shown to be related to the growth rate. The group I enzymes were repressed at high growth rates, while the group II enzymes were derepressed. Each enzyme exhibits a different dependence. The enzyme pattern is shown to depend on the rate of substrate consumption as well as on the type of metabolism and to be correlated with the budding cycle. The enzyme pattern is considered to be controlled by changes of intracellular catabolic or metabolic conditions inherent in the division cycle.
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PMID:Enzyme pattern and aerobic growth of Saccharomyces cerevisiae under various degrees of glucose limitation. 438 90

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

Thermoanaerobium brockii was shown to catabolize glucose via the Embden-Meyerhof-Parnas pathway into ethanol, acetic acid, H(2)-CO(2), and lactic acid. Radioactive tracer studies, employing specifically labeled [(14)C]glucose, demonstrated significant fermentation of (14)CO(2) from C-3 and C-4 of the substrate exclusively. All extracts contained sufficient levels of activity (expressed in micromoles per minute per milligram of protein at 40 degrees C) to assign a catabolic role for the following enzymes: glucokinase, 0.40; fructose-1,6-diphosphate aldolase, 0.23; glyceraldehyde-3-phosphate dehydrogenase, 1.73; pyruvate kinase, 0.36; lactate dehydrogenase (fructose-1,6-diphosphate activated), 0.55; pyruvate dehydrogenase (coenzyme A acetylating), 0.53; hydrogenase, 3.3; phosphotransacetylase, 0.55; acetaldehyde dehydrogenase (coenzyme A acetylating), 0.15; ethanol dehydrogenase, 1.57; and acetate kinase, 1.50. All pyridine nucleotide-linked oxidoreductases examined were specific for nicotinamide adenine dinucleotide, except ethanol dehydrogenase which displayed both nicotinamide adenine dinucleotide- and nicotinamide adenine dinucleotide phosphate-linked activities. Fermentation product balances and cell growth yields supported the glucose catabolic pathway described. Representative balanced end product yields (in moles per mole of glucose fermented) were: ethanol, 0.94; l-lactate, 0.84; acetate, 0.20; CO(2), 1.31; and H(2), 0.50. Growth yields of 16.4 g of cells per mole of glucose were demonstrated. Both growth and end product yields varied significantly in accordance with the specific medium composition and incubation time.
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PMID:Glucose fermentation pathway of Thermoanaerobium brockii. 676 5

Reduced oxygenation of a variety of cells results in transcriptional upregulation of several genes, including the hematopoietic hormone erythropoietin, the angiogenic vascular endothelial growth factor (VEGF), and glycolytic enzymes such as aldolase. Recently, the heme protein cytochrome b558 of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase complex has been proposed as a key component of the oxygen-sensing mechanism. Cytochrome b558 consists of the p22phox and gp91phox subunits and is essential for superoxide generation in phagocytes and B lymphocytes. Mutations in these subunits result in cytochrome b558-negative chronic granulomatous disease (cytb- CGD), an inherited disorder in humans characterized by reduced microbicidal activity due to deficient superoxide generation. To test whether NADPH oxidase is involved in oxygen sensing, we exposed wild-type B-cell lines as well as cytb- CGD-derived B cell lines, deficient in either p22phox or gp91phox, to hypoxia (1% oxygen) or CoCl2 (100 mumol/L) and compared the mRNA levels of VEGF and aldolase with the untreated controls. Northern blot analysis revealed unimpaired basal and inducible expression of VEGF and aldolase mRNA in all four cytb- CGD-derived B-cell lines compared with wild-type cells. Furthermore, reconstitution of cytochrome b558 expression in cytb- CGD-derived B cells by transfection with p22phox or gp91phox expression vectors did not modify VEGF and aldolase mRNA expression. Thus, cytochrome b558 of the NADPH oxidase complex appears not to be essential for hypoxia-activated gene expression and can be excluded as a candidate for the putative universal oxygen sensor.
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PMID:Hypoxic induction of gene expression in chronic granulomatous disease-derived B-cell lines: oxygen sensing is independent of the cytochrome b558-containing nicotinamide adenine dinucleotide phosphate oxidase. 855

The investigations were carried out on 20 men (aged 32-48), hospitalized after lower extremity fractures, in whom no systemic diseases or disorders were found. The activity of glucose-6-phosphate dehydrogenase (G6P-DH), aldolase (A1), lactate dehydrogenase (LDH) and the concentrations of pyruvate, lactate, nicotinamide-adenine dinucleotide (NAD), nicotinamideadenine dinucleotide phosphate (NADP), adenosine-5'-triphosphate (ATP), adenosine-5'-diphosphate (ADP), adenosine -5'-monophosphate (AMP) and 2,3-diphosphoglycerate (2,3-DPG) in erythrocytes taken from patients were estimated. After a two-week hypokinesia G6P-DH, A1, LDH activities and ATP, ADP, AMP concentrations decreased, whereas other estimated parameters did not differ from the control levels. During a 30-day hypokinesia of patients with fractures of the lower extremity a transient decrease of erythrocyte metabolic activity was observed after two weeks. off
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PMID:Red blood cell metabolism in men during long term bed rest. 890 9

This paper presents a modified method of enzymatic assay for Fructose-1,6-diphosphate(FDP). FDP is split to dihydroxyacetone phosphate (DAP) and glyceraldehyde-3-phosphate (GAP) by the action of aldolase. DAP is hydrolyzed at room temperature to free triose. Under alkaline conditions, the free triose is reacted with 2,4-dinitrophenylhydrazine (DNPH), yielding a 2,4-dinitrophenylhydrazine derivative which dissolve in alkali forming a purple color mixture, with maximum absorption at 540.nm. It is proportional to the contents of FDP. Because the method depends on the colorimetric determination of triose formed from fructose-1,6-diphosphate only by aldolase, glycerophosphate dehydrogenase/triosephosphate isomerase (GDH/TIM) and reduced nicotinamide adenine dinucleotide (NADH) which usually applied in multienzymatic method, are omitted in the modified method. The method is specific, convenient and accuracy for the determination of FDP.
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PMID:[Determination of fructose-1,6-diphosphate with aldolase-DNPH by the colorimetric method]. 1128 59

Capillary electrophoresis and on-column enzyme-catalyzed microreactor techniques were used to quantitate the reaction projects resulting from three model systems: i) the conversion of nicotinamide adenine dinucleotide (NAD) to nicotinamide adenine dinucleotide, reduced form (NADH) in the oxidation of glucose-6-phosphate (glc-6-p) to 6-phosphogluconate by glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49); ii) the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP) and adenosine monophosphate (AMP) by hexokinase (HK, EC 2.7.1.1) and apyrase (APY, EC 3.6.1.5), respectively, in the conversion of glucose to glucose-6-phosphate and inorganic phosphate, respectively, and; iii) the conversion of fructose-1,6-bisphosphate to dihydroxyacetone phosphate and glyceraldehyde-3-phosphate by fructose-biphosphate aldolase (ALD, EC 4.1.2.13). Single and double microreactor techniques employing direct or indirect detection were used to follow the conversion of substrate to product(s). In addition, electrophoresis conditions including voltage, enzyme concentration, and mixing time of the reaction, were correlated to product distribution profiles.
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PMID:On-column enzyme-catalyzed microreactions using capillary electrophoresis: quantitative studies. 1193 61

Vitamin B(6)-dependent enzymes may be grouped into five evolutionarily unrelated families, each having a different fold. Within fold type I enzymes, L-threonine aldolase (L-TA) and fungal alanine racemase (AlaRac) belong to a subgroup of structurally and mechanistically closely related proteins, which specialised during evolution to perform different functions. In a previous study, a comparison of the catalytic properties and active site structures of these enzymes suggested that they have a catalytic apparatus with the same basic features. Recently, recombinant D-threonine aldolases (D-TAs) from two bacterial organisms have been characterised, their predicted amino acid sequences showing no significant similarities to any of the known B(6) enzymes. In the present work, a comparative structural analysis suggests that D-TA has an alpha/beta barrel fold and therefore is a fold type III B(6) enzyme, as eukaryotic ornithine decarboxylase (ODC) and bacterial AlaRac. The presence of both TA and AlaRac in two distinct evolutionary unrelated families represents a novel and interesting example of convergent evolution. The independent emergence of the same catalytic properties in families characterised by completely different folds may have not been determined by chance, but by the similar structural features required to catalyse pyridoxal phosphate-dependent aldolase and racemase reactions.
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PMID:Threonine aldolase and alanine racemase: novel examples of convergent evolution in the superfamily of vitamin B6-dependent enzymes. 1268 35

Growth of Salinibacter ruber, a red, extremely halophilic bacterium phylogenetically affiliated with the Flavobacterium/Cytophaga branch of the domain Bacteria, is stimulated by a small number of sugars (glucose, maltose, starch at 1 g l(-1)). Glucose consumption starts after other substrates have been depleted. Glucose metabolism proceeds via a constitutive, salt-inhibited hexokinase and a constitutive salt-dependent nicotinamide adenine dinucleotide phosphate (NADP)-linked glucose-6-phosphate dehydrogenase. Glucose dehydrogenase and fructose-1,6-bisphosphate aldolase activity could not be detected. It is therefore suggested that Salinibacter metabolizes glucose by the classic Entner-Doudoroff pathway and not by the Embden-Meyerhof glycolytic pathway or by the modified Entner-Doudoroff pathway present in halophilic Archaea of the family Halobacteriaceae, in which the phosphorylation step is postponed. However, activity of 2-keto-3-deoxy-6-phosphogluconate aldolase could not be detected in extracts of Salinibacter cells, whether or not grown in the presence of glucose.
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PMID:Sugar metabolism in the extremely halophilic bacterium Salinibacter ruber. 1279 4

The intracellular glutathione redox state and the rate of glucose formation were studied in rabbit kidney-cortex tubules. In the presence of substrates effectively utilized for glucose formation, ie, aspartate + glycerol + octanoate, alanine + glycerol + octanoate, malate, or pyruvate, the intracellular reduced glutathione/oxidized glutathione (GSH/GSSG) ratios were significantly higher than those under conditions of negligible glucose production. Changes in the intracellular GSH/GSSG ratio corresponded to those in glucose-6-phosphate content and reduced nicotinamide adenine dinucleotide phosphate/oxidized nicotinamide adenine dinucleotide phosphate (NADPH/NADP(+)) ratio obtained from malate/pyruvate measurements. Gluconeogenesis stimulation by extracellular adenosine triphosphate (ATP) or inosine caused an elevation of the intracellular GSH/GSSG and NADPH/NADP(+) ratios, as well as glucose-6-phosphate level. Surprisingly, in the presence of 5 mmol/L glucose, both the intracellular GSH/GSSG and NADPH/NADP(+) ratios and glucose-6-phosphate content were almost as low as under conditions of negligible glucose synthesis. L-buthionine sulfoximine (BSO)-induced decline in both the intracellular glutathione level and redox state resulted in inhibition of gluconeogenesis accompanied by accumulation of phosphotrioses and a decrease in fructose-1,6-bisphosphate content, while cysteine precursors altered neither GSH redox state nor the rate of glucose formation. In view of the data, it seems likely that: (1) intensive gluconeogenesis rather than extracellular glucose is responsible for maintaining a high intracellular GSH/GSSG ratio due to effective glucose-6-phosphate delivery for NADPH generation via the pentose phosphate pathway; (2) a decline in the intracellular glutathione level and/or redox state causes a decrease in glucose synthesis resulting from a diminished flux through aldolase; (3) induced by cysteine precursors, elevation of the intracellular GSH level does not affect the rate of glucose formation, probably due to no changes in the intracellular GSH/GSSG ratio.
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PMID:Relationship between gluconeogenesis and glutathione redox state in rabbit kidney-cortex tubules. 1280 Jan 1


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