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)

Activities of enzymes involved in fructose metabolism were measured in samples of human kidney cortex and medulla. The enzymes are ketohexokinase, aldolase, NAD- and NADP-dependent alcohol dehydrogenase, aldehyde dehydrogenase, triokinase and glycerate kinase; hexose biphosphatase and sorbitol dehydrogenase were also investigated. With the exception of glycerate kinase, all enzymes involved in fructose metabolism were found in the human cortex and medulla. The enzyme levels in the medulla were low in comparison with the cortex.
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PMID:Enzymes of fructose metabolism in human kidney. 16 31

The enzyme activities involved in fructose metabolism were measured in human intestine mucosa. Mucosa of the following gut sections were used: duodenum, jejunum, jejunum in the region of the flexura duodenojejunalis, jejunum distal region, ileum middle region and ileum in the region of the valvula ileo coecalis. Ketohexokinase, aldolase, alcohol dehydrogenases NAD- and NADP- dependent were found in all gut sections. The activity of aldehyde dehydrogenase was low in all sections tested. Triokinase could be found only in the duodenum and jejunum region and was absent in the ileum. Glycerate kinase was not present in the human intestine mucosa.
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PMID:Enzymes of fructose metabolism in human small intestine mucosa. 16 32

Aspergillus nidulans was completely devoid of fruit bodies when grown on manganese deficient cultures. This result was shown earlier to be due to a lack of alpha-1,3 glucan in the cell wall. Several enzymes of carbon and nitrogen metabolism were investigated in an attempt to explain the absence of this reserve material. Synthesis of glucose-6-phosphate dehydrogenase, phosphoglucoisomerase and aldolase, were not strongly affected by manganese deficiency. However, phosphoglucomutase showed only 60% of the activity of the control cultures and it was argued that this was connected with the low amounts of alpha-1,3 glucan synthesized. Malate dehydrogenase was the enzyme the least affected by manganese deficiency and the two to threefold higher activity measured after glucose depletion might indicate the induction of the glyoxylate cycle. An impaired glutamine synthetase could explain the increase in activity observed for NAD-glutamine dehydrogenase.
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PMID:Sexual differentiation in Aspergillus nidulans: the requirement for manganese and the correlation between phosphoglucomutase and the synthesis of reserve material. 17 48

1. The regulation of glycolysis and pyruvate oxidation under varying conditions of ATP and oxygen consumption was studied in isolated perfused rat hearts. Potassium-induced arrest was employed to inhibit the ATP consumption of the heart. 2. Under the experimental conditions, the beating heart used solely glucose as the oxidisable substrate. The glycolytic flux through the aldolase step decreased in pace with the decreasing oxygen consumption during the potassium-induced arrest of the heart. The decrease in glucose oxidation was larger than the inhibition of the oxygen consumption, suggesting that the arrested heart switches to fatty acid oxidation. The time course and percentage changes of the inhibition of pyruvate oxidation and the decrease in the amount of the active form of pyruvate dehydrogenase suggest that the amount of active pyruvate dehydrogenase is the main regulator of pyruvate oxidation in the perfused heart. 3. To test the relative significance of the possible mechanisms regulating covalent interconversions of pyruvate dehydrogenase, the following parameters were measured in response to the potassium-induced cardiac arrest: concentrations of pyruvate, acetyl-CoA, CoA-SH, citrate, alpha-oxoglutarate, ATP, ADP, AMP, creatine, creatine phosphate and inorganic phosphate and the mitochondrial NADH/NAD+ ratio. In cardiac tissue the adenylate system is not a good indicator of the energy state of the mitochondrion, even when the concentrations of AMP and free cytosolic ADP are calculated from the adenylate kinase and creatine kinase equilibria. Only creatine phosphate and inorganic phosphate undergo significant changes, but evidence of the participation of the latter compounds in the regulation of the pyruvate dehydrogenase interconversions is lacking. The potassium-induced arrest of the heart resulted in a decrease in pyruvate, a slight increase in acetyl-CoA, a large increase in the concentration of citrate and an increase in the mitochondrial NADH/NAD+. The results can be interpreted as showing that in the heart, the pyruvate dehydrogenase interconversions are mainly regulated by the pyruvate concentration and the mitochondrial redox state. Concentrations of all the regulators tested shifted to directions which one would expect to result in a decrease in the amount of active pyruvate dehydrogenase, but the changes were quite small. Therefore, the energy-linked regulation of pyruvate dehydrogenase in intact tissue is possibly mediated by the equilibrium relations between the cellular redox state and the phosphorylation potential recently confirmed in cardiac tissue.
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PMID:Energy-linked regulation of glucose and pyruvate oxidation in isolated perfused rat heart. Role of pyruvate dehydrogenase. 18 44

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

Extracts of Pseudomonas citronellolis cells grown on glucose or gluconate possessed all the enzymes of the Entner-Doudoroff pathway. Gluconokinase and either or both 6-phosphogluconate dehydratase and KDPG aldolase were induced by growth on these substrates. Glucose and gluconate dehydrogenases and 6-phosphofructokinase were not detected. Thus catabolism of glucose proceeds via an inducible Entner-Doudoroff pathway. Metabolism of glyceraldehyde 3-phosphate apparently proceeded via glyceraldehyde 3-phosphate dehydrogenase, phosphoglycerate kinase, phosphoglycerate mutase, enolase and pyruvate kinase. These same enzymes plus triose phosphate isomerase were present in lactate-grown cells indicating that synthesis of triose phosphates from gluconeogenic substrates also occurs via this pathway. Extracts of lactate grown-cells possessed fructose diphosphatase and phosphohexoisomerase but apparently lacked fructose diphosphate aldolase thus indicating either the presence of an aldolase with unusual properties or requirements or an alternative pathway for the conversion of triose phosphate to fructose disphosphate. Cells contained two species of glyceraldehyde 3-phosphate dehydrogenase, one an NAD-dependent enzyme which predominated when the organism was grown on glycolytic substrates and the other, an NADP-dependent enzyme which predominated when the organism was grown on gluconeogenic substrates.
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PMID:Enzymatic analysis of the pathways of glucose catabolism and gluconeogenesis in Pseudomonas citronellolis. 23 56

The mechanism of 3-dehydroquinate synthase was explored by incubating partially purified enzyme with mixtures of [1-14C]3-deoxy-D-arabino-heptulosonic acid 7-phosphate (DAHP) and one of the specifically tritiated substrates [4-3H]DAHP, [5-3H]DAHP, [6-3H]DAHP, (7RS)-[7-3H]DAHP, (7R)-[7-3H]DAHP, or (7S)-[7-3H]DAHP. Kinetic and secondary 3H isotope effects were calculated from 3H:14C ratios obtained in unreacted DAHP, 3-dehydroquinate, and 3-dehydroshikimate. 3H was not incorporated from the medium into 3-dehydroquinate, indicating that a carbanion (or methyl group) at C-7 is not formed. A kinetic isotope effect kH/k3H of 1.7 was observed at C-5, and afforded support for a mechanism involving oxidation of C-5 with NAD. A similar kinetic isotope effect was found at C-6 owing to removal of a proton in elimination of phosphate, which is reasonably assumed to be the next step in 3-dehydroquinate synthase. Hydrogen at C-7 of DAHP was not lost in the cyclization step of the reaction, indicating that the enol formed in phosphate elimination participated directly in an aldolase-type reaction with the carbonyl at C-2. In the dehydration of 3-dehydroquinate to 3-dehydroshikimate the (7R) proton from (7RS)- or (7R)-[7-3H]DAHP is lost, indicating that the 7R proton occupies the 2R position in dehydroquinate. Hence the cyclization step occurs with inversion of configuration at C-7. A kinetic isotope effect kH/k3H = 2.3 was observed in the conversion of (2R)-[2-3H]dehydroquinate to dehydroshikimate. Hence loss of a proton from the enzyme-dehydroquinate imine contributed to rate limitation in the reaction.
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PMID:Isotope effects in 3-dehydroquinate synthase and dehydratase. Mechanistic implications. 34 12

Biotin deficiency resulted in an increased growth rate of Aspergillus nidulans. The activities of hexokinase and aldolase were not much changed during the growth cycle, but activities of glucose-6-phosphate dehydrogenase and NADP-linked glutamate dehydrogenase increased significantly during the exponential phase. This change was remarkable during biotin deficiency. In contrast to the higher growth rate and respiration rate during biotin deficiency the activities of NAD(P)H oxidoreductases were low. An inverse relationship between the activity of tyrosinase and melanin content was observed. A role of the DOPA-DOPA-quinone system in maintaining culture growth is suggested.
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PMID:Growth, glucose metabolism and melanin formation in biotin-deficient Aspergillus nidulans. 40 7

The dermal cells in grey, xanthic, and white goldfish integuments were cytochemically characterized for the following enzymatic activities: tyrosinase, DOPA-oxidase, cytochrome oxidase, monoamine oxidase, peroxidase, non-specific esterase, cholinesterase, NAD-diaphorase, NADP-diaphorase, aryl sulfatase, nucleotide phosphodiesterase, beta-glucuronidase, acid phosphatase, alkaline phosphatase, adenosine triphosphatase, thiamine pyrophosphatase, glucose-6-phosphatase, aldolase, as well as succinate, malate, isocitrate, glutamate, glucose-6-phosphate, 6-phosphogluconate, alpha-glycerophosphate, alcohol, lactate, and beta-hydroxybutyrate dehydrogenases. It was found that the epidermis was a significant barrier to the access of cytochemical reaction substrates. Removal of the epidermal barrier provided dermal cell localizations of enzymatic activities which were reproducible. Further, alterations in reaction times and temperatures from the mammalian methodology provided conditions fe various integumental cells were compared for possible interrelationships. The basic foundations for future work with the dermis of poikilothermic vertebrates on an experimental basis were established. In addition, a previously undescribed non-pigmented dermal cell, the "x"-cell, was found to have enzymatic characteristics similar to both melanophores and lipophores. The "x"-cell may be the common precursor of both types of pigment cells.
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PMID:Cytochemical characterization of goldfish (Carassius auratus L.) dermis with special reference to the pigment cells. 82 86

Soluble enzymes were immobilized and visualized by polyacrylamide gel slabs, impregnated with the incubation medium including auxiliary enzymes. The method has several advantages over existing techniques which make use of gel films or a semipermeable membrane. The diffusion of tissue compounds is effectively limited, while auxiliary enzymes may be operative. Moreover the viscosity of the medium is temperature-independent so that the incubation temperature can be varied. To demonstrate the suitability of the method glycerol-3-phosphate dehydrogenase, lactate dehydrogenase, glucose-6-phosphate dehydrogenase, hexokinase, phosphoglucomutase and aldolase were visulaized in human or rat skeletal muscle. Cytosolic and mitochondrial glycerol-3-phosphate dehydrogenase were both visualized in the absence of added NAD+ and menadione. For the visualization of ATP producint enzymes, like creatine kinase and pyruvate kinase, the method is not suitable.
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PMID:Polyacrylamide gel technique for the histochemical demonstration of soluble enzymes. 105 94


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