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)

Cell suspensions of Bacteroides fragilis were allowed to ferment glucose and lactate labeled with (14)C in different positions. The fermentation products, propionate and acetate, were isolated, and the distribution of radioactivity was determined. An analysis of key enzymes of possible pathways was also made. The results of the labeling experiments showed that: (i) B. fragilis ferments glucose via the Embden-Meyerhof pathway; and (ii) there was a randomization of carbons 1, 2, and 6 of glucose during conversion to propionate, which is in accordance with propionate formation via fumarate and succinate. The enzymes 6-phosphofrucktokinase (pyrophosphate-dependent), fructose-1,6-diphosphate aldolase, phosphoenolpyruvate carboxykinase, malate dehydrogenase, fumarate reductase, and methylmalonyl-coenzyme A mutase could be demonstrated in cell extracts. Their presence supported the labeling results and suggested that propionate is formed from succinate via succinyl-, methylmalonyl-, and propionyl-coenzyme A. From the results it also is clear that CO(2) is necessary for growth because it is needed for the formation of C4 acids. There was also a randomization of carbons 1, 2, and 6 of glucose during conversion to acetate, which indicated that pyruvate kinase played a minor role in pyruvate formation from phosphoenolpyruvate. Phosphoenolpyruvate carboxykinase, oxaloacetate decarboxylase, and malic enzyme (nicotinamide adenine dinucleotide phosphate-dependent) were present in cell extracts of B. fragilis, and the results of the labeling experiments agreed with pyruvate synthesis via oxaloacetate and malate if these acids are in equilibrium with fumarate. The conversion of [2-(14)C]- and [3-(14)C]lactate to acetate was not associated with a randomization of radioactivity.
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PMID:Pathway of succinate and propionate formation in Bacteroides fragilis. 14 60

The properties of 12 enzymes related to the glycolytic and oxidative metabolism of glucose were examined in normal and malignant epithelium of human uterine tissues to develop optimised assays suitable for both types of tissue and to delineate important kinetic differences that may exist between them. All assays gave acceptable long-term precision, although instability of phosphofructokinase and 6-phosphogluconate dehydrogenase prevented proper assessment; and all were linear with concentration to an absorbance change of 0.04/min, or more in the case of several enzymes. Notable differences between pyruvate kinase of normal and malignant uterine epithelium were found with D-fructose-1,6-diphosphate (FDP) which caused significantly greater activation of the latter as well as a dramatic reduction in Km for phosphoenol pyruvate; inhibition by DL-alanine was greater for pyruvate kinase of malignant than normal cervix epithelium, whereas endometrium did not show this difference. The ratio of aldolase activity with FDP to that with D-fructose-1-phosphate was greater in malignant than in normal cervix epithelium, no significant difference being apparent in endometrium.
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PMID:Properties of glycolytic and related enzymes of normal and malignant human uterine tissues studied to optimise assay conditions. 15 96

A host response to infection by Coxiella burneti was investigated. Infectedyolk sacs were harvested from embryonated eggs and assayed for glycolytic activity. Assays of glycolytic enzymes included glucose isomerase, aldolase, phosphofructokinase,fructose-1,6-diphoshatase, glyceraldehyde-3-phosphate dehydrogenase, enolase, and pyruvate kinase. No significant differences in enzymatic activity between normal and infected tissues through the 12th day was observed. From the 13th day through the 16thday, the glycolytic activity of normal tissues decreased. Glycolytic activity of infected tissues did not decrease, but showed a gradual increase during this same time period. Embryos from infected eggs demonstrated a gradual decrease in total weight fromthe 12th day until death occurred on the 16th day.
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PMID:Host response to infection by Coxiella burneti. 16 99

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

Seven subjects were fed a 3,000 kcal defined formula diet daily for 19 days. Except for one 5-day period, 50% of the total caloric intake was provided as either oral or intravenous glucose. The study was divided into four periods as follows: period I lasted 5 days and provided 50% of calories as glucose; period II lasted 5 days and provided no carbohydrate (70% fat and 30% protein); period III lasted 4 days and provided 50% of calories as intravenous glucose and 50% of calories as oral fat plus protein; period IV lasted 5 days and provided 50% of calories as oral glucose. Intestinal biopsy specimens were taken on days 3 and 5 of each period, except period III when biopsies were done only on day 4. No change in intestinal morphology occurred during the study. The carbohydrate-free diet caused the alpha-glucosidase (maltase and sucrase) activities to decrease significantly from that seen with the glucose diet. Sucrase decreased from 14.4 +/- 1.0 to 7.1 +/- 0.9 mumoles/min per g tissue and maltase decreased from 56.1 +/- 3.4 to 30.0 +/- 2.1 mumoles/min per g tissue. Glycolytic enzyme activities decreased during the carbohydrate-free period (pyruvate kinase decreased from 236 +/- 12 to 78 +/- 8, fructose 1-phosphate aldolase decreased from 147 +/- 6 to 53 +/- 4, fructose-1,6-diphosphate aldolase decreased from 151 +/- 8 to 55 +/- 3, and hexokinase decreased from 21 +/- 3 to 7 +/- 1 nmoles/min per mg protein, respectively). Intravenous glucose caused no change in disaccharidase activities. The enzyme activities during periods I and IV were identical and significantly higher than during period II with the exception of fructose-1,6-diphosphatase which increased during period II as compared with periods I and IV. These findings provide an explanation for the transient period of decreased tolerance to dietary sugars when patients are weaned from total parenteral feedings to enteral feedings.
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PMID:Comparison of the adaptive changes in disaccharidase, glycolytic enzyme and fructosediphosphatase activities after intravenous and oral glucose in normal men. 17 Aug 20

Trivalent organic antimonials, such as stibophen, have been employed for the chemotherapy of schistosome and filariid infections. The effects of stibophen on adult Litomosoides carinii, Dipetalonema witei (= viteae), and Brugia pahangi were examined. In vitro, lactate accumulation was markedly inhibited by the antimonials as was phosphofructokinase activities in homogenates. Incubation of filariids with stibophen and determination of internal concentrations of hexose phosphate also indicated a decreased phosphofructokinase activity. In addition, a second inhibitory effect of stibophen on aldolase has been observed which appears to be specific for stibophen and is not displayed by potassium antimony tartrate. Both inhibitory activities may contribute to the chemotherapeutic effect of stibophen. In addition to the schistosomes and filariids, stibophen also inhibits Ascaris and Hymenolepis diminuta phosphofructokinases at low concentrations, where no inhibition of the corresponding mammalian liver enzyme was demonstrable.
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PMID:The effects of stibophen on phosphofructokinases and aldolases of adult filariids. 17 64

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

The activity of glycolysis and glyconeogenesis enzymes, content of carbohydrate and nitrogen compounds were studied in muscles of 15-month cattle of different sex of the black-piebald breed and its crosses with bulls of two meat breeds Hereford and Limousine. In the muscles of bulls the activity of phosphoglucomutase, phosphohexoisomerase, aldolase and fructose-1,6-diphosphatase is considerably higher (except of the activity of phosphoglucomutase and phosphohexoisomerase in the muscles of pure-bred black-piebald animals for which difference is not statistically reliable) and the content of glycogen, glucose, fructose, lactic acid, free and phosphorylated pentoses of nonadenylic compounds is essentially lower than in the muscle tissue of heifers of analogous breed groups. A higher activity of carbohydrate metabolism enzymes (especially aldolase and fructose-1,6-diphosphate) and a higher content of total pentoses, the adenylic system pentoses, ATP phosphorus in the muscles of the cross Limousine and Hereford bulls and Limousine heifers as compared to the pure-bred black-piebald animals of the corresponding sex coincide with a greater increase in the muscular tissue and more intensive synthesis of proteins in it. A considerably lower level of glycogen, glucose, fructose and a relatively high activity of carbohydrate metabolism enzymes in the muscles of cross young cattle show that disintegration of these carbohydrates is in excess of their synthesis, that is due to an increase in the energy demand connected with a more intensive synthesis of proteins in the muscular tissue. Therefore, in the authors opinion the performed kill of the cross Limousine and Hereford bulls as well as Limousine heifers, is somewhat untimely and unreasonable. At the same time the activity of all the studied enzymes in the muscles of the cross Hereford heifers, vice versa, is considerably lower as compared to the black-piebald heifers and coincides with a low gain in live weight and muscular tissue, a more rapid accumulation of glycogen and lipids and a more delayed--of proteins in the muscular tissue, that evidences for their early maturity. Therefore the further raising of the cross Hereford heifers in the farm for obtaining meat is economically less profitable. The data obtained give grounds to recommend determination of the activity of carbohydrate metabolism enzymes, especially of aldolase and fructose-1,6-diphosphate, as a test for checking the muscular tissue growth and for prognosing the meat productivity in the growing pure-bred and cross young cattle of different sex.
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PMID:[Activity of carbohydrate-metabolizing enzymes and content of carbohydrate and nitrogen compounds in muscles of young cattle depending on breed and sex]. 17 55

1. Oral administration of ethanol (3 ml) of 95% in 12 ml total volume over a two day period) significantly decrease plasma glucose and insulin levels and the activities of two key gluconeogenic enzymes, pyruvate carboxylase (pyruvate: CO2 ligase (ADP), EC 6.4.1.1) and fructose diphosphatase, (D-Fru-1,6-P2 1-phosphohydrolase, EC 3.1.3.11), and one glycolytic enzyme, fructose-1,6-P2 aldolase (Fru-1,6-P2 D-glyceraldehyde-3-P lyase, EC 4.1.2.13). In each instance, the administration of 2400 mug daily of oral folate in conjuction with the ethanol prevented these alterations in carbohydrate metabolism. 2. Intravenous injection of ethanol produced a rapid decrease (within 10--15 min) in the activities of hepatic phosphofructokinase, (ATP:D-fructose-6-phosphate 6-phosphotransferase, EC 2.7.1.11), pyruvate kinase, (ATP:pyruvate phosphotransferase, EC 2.7.1.40), fructose diphosphatase and fructose-1,6-P2 aldolase. 3. Intravenous ethanol significantly increased hepatic cyclic AMP concentration approximately 60% within 10 min, while oral ethanol did not alter hepatic cyclic AMP concentrations. 4. These data confirm the known antagonism ethanol and folate and suggest that oral folate might offer a protective effect against hypoglycemia in rats receiving ethanol.
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PMID:Acute effects of oral and intravenous ethanol on rat hepatic enzyme activities. 17 81

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


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