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)

Strain NP 315 of Escherichia coli possesses a thermolabile fructose-1, 6-diphosphate (FDP) aldolase; its growth on carbohydrate substrates is inhibited probably as a consequence of the accumulation of high intracellular levels of FDP. Studies of one class of phenotypic revertants of strain NP 315 which have regained their ability to grow on C(6) substrates at 40 C showed that in these strains the buildup of the inhibitory FDP pool is prevented by additional mutations in enzymes catalyzing the conversion of the substrate offered in the medium to FDP. For example, mutations affecting 6-phosphogluconate dehydrogenase activity (gnd(-)) may be selected in great number without any mutagenesis and enrichment simply by isolating revertants of strain NP 315 able to grow on gluconate at 40 C. Similarly, an additional mutation in phosphoglucose isomerase (pgi(-)) restores the ability of these fda(-)gnd(-) strains to grow on glucose at 40 C. Glucose metabolism of these fda(-)gnd(-)pgi(-) strains was investigated. The enzymes of the Entner-Doudoroff pathway are induced to an appreciable extent upon growth of these mutants on glucose medium; further evidence for glucose degradation via this route (which normally is induced only in the presence of gluconate) was provided by following the fate of the C1 label of radioactive glucose in l-alanine. Predominant labeling of the carboxyl-carbon of l-alanine was observed, inciating a major contribution of the Entner-Doudoroff path to pyruvate formation from glucose. Chromatographic analysis of the intermediates of glucose metabolism showed further that glucose apparently is at least partly metabolized via a bypass consisting of the accumulation of extracellular gluconic acid which arises by dephosphorylation of 6-phosphogluconolactone and possibly of 6-phosphogluconate. This extracellular gluconate is then taken up and metabolized in the normal manner via the Entner-Doudoroff enzymes.
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PMID:Phenotypic suppression of a fructose-1,6-diphosphate aldolase mutation in Escherichia coli. 457 44

Spirillum itersonii ATCC 12639 utilized d-fructose but neither d-glucose nor d-gluconate as a sole source of carbon and energy. The substrate saturation kinetics for d-fructose and d-glucose uptake by whole cells indicated the presence of a carrier-mediated transport system for d-fructose but not for d-glucose. The d-fructose uptake activity was induced (10- to 12-fold increase) during growth on d-fructose-Casamino Acids (CA) or d-glucose-CA medium, but not CA alone. d-Fructose uptake activity was stimulated by Na(+) or Li(+), but was inhibited by KCN, NaN(3), 2,4-dinitrophenol, and p-chloromercuribenzoate. High specific activities of glucokinase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydratase, and 2-keto-3-deoxy-6-phosphogluconate aldolase were detected in extracts of cells cultured on d-fructose-CA medium. These enzymatic activities were undetectable in extracts of cells grown in CA or succinate-CA medium. No decrease in the maximally induced specific activities of these enzymes occurred after the addition of succinate to cells during exponential growth on d-fructose-CA. Fructose 1,6-diphosphate aldolase and glucose-6-phosphate isomerase specific activities were approximately the same irrespective of cultural conditions. These results indicated that d-glucose was not utilized by cells of S. itersonii because this bacterium was impermeable to this hexose.
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PMID:Transport and catabolism of D-fructose by Spirillum itersomii. 480 97

Infection of white rats with Francisella tularensis (Pasteurella tularensis) and Salmonella typhimurium and exposure to the endotoxin of S. typhimurium stimulated significant increases in various serum enzymes including aldolase, lactate dehydrogenase, phosphohexose isomerase, isocitrate dehydrogenase, and glutamate-oxalacetate transaminase. The rates of changes in enzymatic activity after infection were directly related to the size of infecting dose and to the type of infective agent employed. Tularemic infection stimulated excessive changes in enzyme activity, whereas salmonellosis and endointoxication elicited less pronounced alterations of relatively short duration. Changes observed in serum enzymes after exposure to these agents reflect the severe liver damage and extensive systemic involvement noted in tularemia as opposed to more localized and less intensive tissue damage occurring during salmonellosis and endointoxication.
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PMID:Influence of bacterial infection on serum enzymes of white rats. 488 56

Experiments were run on three groups of healthy guinea pigs. One group was given ethionamide, kanamycin and PASA another was given ethionamide, kanamycin and pyrazinamide while the third served as a control. These studies permitted to establish that the above drugs affect the activity of enzymes involved in the metabolism of carbohydrates and nucleic acids. Activity of glucose-6-phosphatase and aldolase significantly decreased in liver, brain and lung tissue. At the same time, activity of deoxyribonuclease and ribonuclease in the tissues concerned sharply increased. Changes in activity of phosphohexose isomerase, lactate dehydrogenase and aminotransferases in these tissues was statistically insignificant.
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PMID:[Effect of various combinations of antibacterial drugs on enzyme activity in guinea pig tissues]. 531 14

Clostridium thermocellum was shown to ferment glucose in a medium containing salts and 0.5% yeast extract. An active glucokinase was obtained with improved conditions for growth, assay, and preparation of cell extracts. Cell extracts appear to contain a glucokinase inhibitor that interferes with the assays at high protein concentrations. Glucokinase activity is stimulated about 60% by pretreatment with dithiothreitol. Little or no fructokinase or mannokinase activity was detected in cell extracts. The absence of glucokinase in mannitol-grown cells, the increase in glucokinase activity upon incubation of cell suspensions with glucose, and the lack of increase in activity when chloramphenical is added are evidence that glucokinase is an inducible enzyme. The following enzymes were detected in cell extracts (the enzyme activities are shown in parentheses are micromoles per minute per milligram or protein at 27 C): glucokinase (0.48), phosphoglucose isomerase (0.73), fructose 6-phosphate kinase (0.24), fructose diphosphate aldolase (0.59), glyceraldehyde 3-phosphate dehydrogenase (0.53), triose phosphate isomerase (0.13), phosphoglycerate kinase (0.20), phosphoglycerate mutase (0.20), enolase (0.28), pyruvic kinase (0.13), and lactic dehydrogenase (0.13). Glucose 6-phosphate dehydrogenase activity was absent or very low (0.0002) and 6-phosphogluconate dehydrogenase activity also was relatively low (0.015). From these data, it is proposed that carbohydrate metabolism in C. thermocellum proceeds by the Embden-Meyerhof pathway.
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PMID:Utilization of glucose by Clostridium thermocellum: presence of glucokinase and other glycolytic enzymes in cell extracts. 554 Oct 8

Plasma LDH levels were determined in normal and Riley virus-infected mice following treatment with various drugs known to alter the activity of the RES. The rise in plasma LDH level after Riley virus infection was considerably enhanced by previous treatment with thorotrast (to produce blockade of the RES), and decreased by previous treatment with stilboestrol (to stimulate the RES). A dose of 2000 r whole-body x-irradiation, lethal within 3 to 4 days, did not alter the phagocytic activity of the RES, and was without effect on plasma LDH activity in normal mice, or on the rise in plasma LDH level following infection with Riley virus. Blockade of the RES with cholesterol oleate, thorotrast, or zymosan, resulted in a 2- to 3-fold rise in plasma LDH level within a few hours. The level returned to normal by 1 to 3 days. Stimulation of the RES with stilboestrol resulted in a decrease in plasma LDH level by 1 to 2 days in both normal and infected mice, with a return to normal by about a week. Blockade of the RES in uninfected mice with thorotrast or cholesterol oleate, besides increasing the plasma LDH level caused a rise in plasma phosphoglucose isomerase level, but no significant alterations in plasma aldolase or alanine transaminase levels, studied up to 10 days. Riley virus causes a similar pattern of enzyme elevation. It is suggested that the increased levels of certain plasma enzymes in Riley virus-infected mice may be due to competitive inhibition by virus particles of plasma enzyme clearance by the RES.
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PMID:Studies on the mechanism of action of Riley virus. I. Action of substances affecting the reticuloendothelial system on plasma enzyme levels in mice. 585 75

Red cell enzymes, 2,3-diphosphoglycerate (2,3-DPG) and adenosine triphosphate (ATP), were evaluated in a 23-mo-old boy with juvenile chronic myelocytic leukemia (JCML) at the onset of his illness and 6 mo later during the accelerated phase. The activities of the age-dependent red cell enzymes, hexokinase, aldolase, pyruvate kinase, and glucose-6-phosphate dehydrogenase, were elevated, as were the concentrations of red cell 2,3-DPG and ATP, consistent with a young red cell population metabolizing at an increased glycolytic rate. The activities of the non-age-dependent enzymes, glyceraldehyde-3-phosphate dehydrogenase (G3PD), phosphoglycerate kinase, and enolase, were also increased to levels similar to or greater than those observed in term infants. As the illness progressed, the activity of red cell G3PD increased further, and phosphoglucose isomerase activity increased markedly. These results are consistent with the prior suggestion that JCML represents a reversion to "fetal" erythropoiesis.
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PMID:Fetal erythropoiesis in juvenile chronic myelocytic leukemia. 622 20

Clostridium sporogenes 272 has a high rate of glucose fermentation. Its cell-free extract contains all glycolytic enzymes catalysing glucose degradation to pyruvate and shows the phosphoroclastic activity. C. sticklandii CSG has a low rate of glucose fermentation. Hence, the activity of the following enzymes is lower in this organism comparing to C. sporogenes: phosphohexoisomerase (EC 5.3.1.9), phosphofructokinase (EC 2.7.1.11), aldolase (EC 4.1.2.13), triosephosphate isomerase (EC 5.3.1.1) and glyceraldehyde phosphate dehydrogenase (EC 1.2.1.12). Moreover, it is possible that the system of glucose transport into the cell is damaged in C. sticklandii.
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PMID:[Glucose metabolism in Clostridium sporogenes and Clostridium sticklandii bacteria]. 623 May 11

The activities of phosphofructokinase, aldolase and pyruvate kinase were diminished in extracts from skeletal muscle of streptozotocin diabetic rats, whereas the activities of glucose phosphate isomerase and phosphoglucomutase were not changed. Treatment of diabetic rats with insulin restored the activity of phosphofructokinase to normal. A kinetic study of the partially purified enzyme from normal and diabetic rats showed identical Michaelis constants for ATP and equal sensitivity to inhibition by excess of this substrate. Extracts of quick frozen muscle from diabetic rats had higher levels of citrate (an inhibitor of phosphofructokinase) and lower levels of D-fructose-1,6-bisphosphate and D-glucose-1,6-bisphosphate (activators of this enzyme). The levels of D-fructose-6-phosphate, D-glucose-6-phosphate, ATP, ADP and AMP were the same for the two groups. Our data suggest that the in vivo decrease of phosphofructokinase activity in skeletal muscle of diabetic rats is due to a decrease in the level of the enzymatically active protein as well as to an unfavorable change in the level of several of its allosteric modulators.
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PMID:Decreased phosphofructokinase activity in skeletal muscle of diabetic rats. 623 37

The activities of glycolytic enzymes were determined in human autoptic temporal lobes from patients with different forms of dementia. For some enzymes (hexokinase, phosphofructokinase and phosphoglycerate mutase) the effect seen in dementia can be regarded as an intensification of the normal ageing affect. For other enzymes (aldolase, phosphoglucose isomerase, triosephosphate isomerase and lactate dehydrogenase) no changes in enzyme activities corresponding to those found in dementia are observed in the normal ageing process. These effects are most pronounced in the non-vascular Alzheimer cases. With the exception of triosephosphate isomerase and lactate dehydrogenase, enzyme activity is also reduced in bronchopneumonia. The effects of dementia and bronchopneumonia on the activities of glycolytic enzymes in human autoptic brain tissue are often difficult to distinguish.
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PMID:Glycolytic enzymes from human autoptic brain cortex: normal aged and demented cases. 625 57


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