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 influence of fructose feeding for 1 to 12 days on the activity of enzymes of glycolysis and gluconeogenesis was studied in the jejunal mucosa and the liver of rats. In the jejunal mucosa fructose feeding leads to an increase in the activity of 6-phosphofructokinase (p less than 0.05) and fructose-1.6-bisphosphate aldolase (p less than 0.05), while the activity of hexokinase and glucose-6-phosphate dehydrogenase remains unchanged. Fructose feeding increases the activity of fructose-bisphosphatase in the jejunal mucosa, however, the absolute values of this enzyme remain low (less than 10%) when compared to those in the liver. In the liver fructose feeding is followed by a marked increase of the activity of fructose-bisphosphatase and glucose-6-phosphate dehydrogenase. In contrast, the activity of glucose-6-phosphatase decreases significantly under a fructose enriched diet. The enzyme activity rose to a maximum within 3 days; in the following time of observation no major changes occurred. The results are in accordance with the assumption that fructose feeding leads in the jejunal mucosa mainly to adaptive alterations of the activity of those enzymes which are involved in the breaking-down of fructose, whereas in the liver the activity of those enzymes is increased, which take part in the new synthesis of glucose-6-phosphate or which direct glucose-6-phosphate into the pentose-phosphate.
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PMID:Effect of fructose feeding on the activity of enzymes of glycolysis, gluconeogenesis, and the pentose phosphate shunt in the liver and jejunal mucosa of rats. 727 91

Male, Sprague-Dawley rats were weaned prematurely (post-natal day 17) to a starch-based diet. Compared with normally-weaned rats, prematurely-weaned animals showed increases in the activities of hepatic glucose-6-phosphate dehydrogenase (G6PD) and malic enzyme (ME), and a fall in serum cholesterol level within 1 day. These enzymatic changes occurred sooner and were more pronounced when the diet of prematurely-weaned rats supplied 20% of the energy from sucrose, but the initial fall in serum cholesterol levels was smaller than in animals weaned prematurely to the control diet. Sucrose also led to an early rise in the activity of hepatic triokinase, but did not influence ketohexokinase or fructose-1-phosphate aldolase. Sucrose consumption resulted in an increase in lipogenesis in vivo in the liver and carcass and in serum cholesterol concentration on postnatal day 30, but animals weaned to the control diet were comparable with normally-weaned rats at the time. Early weaning led to elevation in the activities of hepatic G6PD and ME in 122-day-old rats, even though the control diet was fed from the age of 30 days. This response was not altered by the type of carbohydrate fed during the initial weaning period. Sucrose consumption during the weaning period did not exert long-term effects on the activities of hepatic fructolytic enzymes or in serum cholesterol levels.
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PMID:Immediate and late effects of premature weaning of rats to diets containing starch or low levels of sucrose. 728 3

Effect of di-2-ethylhexyl phthalate (DEHP) on glycogen contents and certain enzymes of carbohydrate metabolism of rat liver was investigated. A significant decrease in glycogen content of unfasted and an increase in fasted animals was observed. Blood glucose tolerance was reduced and the rate of both glycogenesis and glycogenolysis, as judged by measuring glycogen contents after feeding labelled and unlabelled glucose, was also decreased. Activities of glucose-6-phosphate dehydrogenase, phosphorylase and glucose-6-phosphatase were significantly decreased while activities of fructose-1-6-diphosphatase and aldolase remained unaltered. The present results suggest that DEHP affects both glycogenesis and glycogenolysis in rat liver.
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PMID:Effect of di-2-ethylhexyl phthalate (DEHP) on glycogen metabolism in rat liver. 741 15

The presence of hexokinase, aldolase, glyceraldehyde-phosphate dehydrogenase, phosphoglycerate kinase, glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase has been detected in Y. enterocolitica, which indicates the glycolytic and pentosophosphate pathways of glucose catabolism. Y. enterocolitica can be classified as an opportunistic anaerobic microorganism on the basis of the whole complex of its characteristics (growth in both aerobic and anaerobic conditions, the reduction of nitrates into nitrites, the presence of higly active glycolytic enzymes).
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PMID:[Glucose metabolism in Yersinia enterocolitica cells]. 743 20

We have previously found that the restoration of cartilage matrical proteoglycans is preceded by markedly increased activity of uridine diphosphoglucose dehydrogenase (UDPGD), an enzyme directly associated with glycosaminoglycan (GAG) synthesis, and by increased activity of enzymes of the major energy yielding pathways (glucose-6-phosphate dehydrogenase (G6PD), glyceraldehyde-3-phosphate dehydrogenase (GAPD) and succinate dehydrogenase (SDH)). We did not find an increase in lactate dehydrogenase (LDH). In the present longitudinal study of rabbits (from 5 weeks to 42 months of age), we looked for age related changes in the activity of these enzymes in auricular chondrocytes, as well as for collagen and GAG content. Collagen content (micrograms/wet weight) increased up to 12 months and remained stable; total GAG content (micrograms/wet weight) reached its maximal value at growth and then declined gradually, reducing the GAG/collagen ratio dramatically from 36 to 8. At any age LDH was two to three times more active than either G6PD, aldolase, or GAPD. SDH and UDPGD activities were even lower. The age related changes varied: (1) LDH and GAPD were stable and did not change with either growing or aging; (2) G6PD and aldolase reached their maximal activity at 3-9 months, followed by a sharp drop at 12 months. G6PD remained stable, while aldolase continued to decline, although more slowly; (3) Maximal activity of SDH and UDPGD was measured at 5 weeks. Thus, the changes in enzyme activity in chondrocytes with age were specific for each enzyme. The significant decline in G6PD, aldolase, the rate-limiting enzymes of the pentose shunt and classic glycolysis, and SDH markedly reduced the ability of chondrocytes to generate energy.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential decline of rabbit chondrocytic dehydrogenases with age. 778 68

Evidence for the presence of the enzymes of the Entner-Doudoroff pathway in Helicobacter pylori was obtained using 1H and 31P nuclear magnetic resonance spectroscopy. Bacterial lysates generated 6-phosphogluconate and NADH or NADPH in incubations with glucose-6-phosphate and NAD+ or NADP+, indicating the presence of glucose-6-phosphate dehydrogenase activities. Formation of pyruvate was observed in time courses of incubations of bacterial lysates with 6-phosphogluconate as the only substrate, suggesting the presence of 6-phosphogluconate dehydratase and 2-keto-3-deoxy-6-phosphogluconate aldolase activities. The existence of these enzymes and of triose phosphate isomerase was confirmed by observing the appearance of dihydroxyacetone phosphate in time courses of bacterial lysates incubated with 6-phosphogluconate. Aldolase activity was measured by the production of pyruvate and dihydroxyacetone phosphate in lysates incubated with 2-keto-3-deoxy-6-phosphogluconate as the sole substrate. Dehydrogenase, dehydratase and aldolase activities were observed in several bacterial strains including wild types from fresh isolates. Kinetic parameters were measured for the three activities. The cellular location of the enzymes was investigated by comparing the activities measured in the pellet and supernatant fractions obtained by centrifugation of lysate suspensions. The concentration of compounds causing 50% inhibition of enzyme activity was determined from dose-response curves. The data suggested the presence of two glucose-6-phosphate dehydrogenases linked to NAD+ and NADP+ activities. Using inhibitors differences between the H. pylori and mammalian KDPG aldolases were detected. The presence of these enzyme activities in H. pylori provided evidence for the existence of the Entner-Douderoff pathway in the bacterium.
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PMID:The Entner-Doudoroff pathway in Helicobacter pylori. 803 47

A method for the fractionation of swine erythrocytes according to age using Percoll is described. Centrifugation of erythrocytes on discontinuous Percoll gradients yielded four fractions of erythrocytes. To ascertain that each fraction of erythrocytes represented a different age group, the activities of hexokinase (Hx), aldolase, glyceraldehyde-3-phosphate dehydrogenase (GAPD), pyruvate kinase (PK), lactate dehydrogenase (LDH), glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) were determined. These enzyme activities decreased successively from the top to the bottom fractions of the centrifuged column. Young erythrocytes obtained from the upper fractions of the centrifuged column exhibited a higher activity of each enzyme than that found in the heavier and older erythrocytes at the bottom fraction. This method is proposed as the most appropriate for use as an aid in distinguishing the presence of a young erythrocyte population.
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PMID:Swine erythrocyte fractionation in Percoll density gradients. 813 69

The pathways of pectin and galacturonate catabolism in Erwinia chrysanthemi converge to form a common intermediate, 2-keto-3-deoxygluconate, which is phosphorylated to form 2-keto-3-deoxy-6-phosphogluconate (KDGP) and then cleaved by the aldolase encoded by the kdgA gene. We cloned the kdgA gene of the E. chrysanthemi strain 3937 by complementing an Escherichia coli kdgA mutation, using an RP4-derivative plasmid. Restriction mapping of the kdgA region and isolation of kdgA-lac fusions allowed the more precise localization of the kdgA gene and determination of its transcriptional direction. The nucleotide sequence of the kdgA region indicated that the kdgA reading frame is 639 bases long, corresponding to a protein of 213 amino acids with a molecular mass of 22,187 Da. Comparison of the deduced primary amino acid sequences of the E. chrysanthemi KDGP-aldolase to the E. coli, Zymomonas mobilis and Pseudomonas putida enzymes showed that they are highly conserved. The E. chrysanthemi kdgA structural gene begins 153 bases downstream of an open reading frame that has a high homology with the zwf E. coli gene encoding glucose-6-phosphate dehydrogenase. The zwf gene is also linked to eda (kdgA) in E. coli and P. putida but genetic organization is different. Regulation of zwf and kdgA expression in E. chrysanthemi was analysed using lacZ fusions. The expression of zwf is independent of the growth rate, but is repressed in the presence of glucose. Induction of kdgA by pectin-degradation products is mediated in vivo by the negative regulatory gene kdgR, which also controls all the steps of pectin degradation.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Molecular analysis of the Erwinia chrysanthemi region containing the kdgA and zwf genes. 814 47

Hormonal inductions of lipogenic enzyme activities (fatty acid synthetase, malic enzyme (ME), glucose-6-phosphate dehydrogenase (G6PD) and ATP-citrate lyase) were studied in primary cultured rat hepatocytes. Insulin, triiodothyronine and dexamethasone markedly stimulated the inductions of the enzymes (particularly G6PD and ME) in the presence of pyruvate. Lactate also induced their activities. The activities of these enzymes in the presence of appropriate hormone combinations and a substrate amount of pyruvate were as high as, or higher than those in the liver of rats on high-carbohydrate, low-fat diet. The aldolase and glucokinase activities induced by these hormones were not enhanced by the addition of pyruvate. The induction by pyruvate was inhibited by actinomycin D or cycloheximide. The ATP content of rat hepatocytes was maintained without increase during culture with pyruvate for 6 days. These results indicate that the additions of pyruvate, or its metabolites to cultures of isolated hepatocytes have specific effects on the inductions of certain hepatic enzymes, possibly acting at the level of transcription. Their effects are similar to those of feeding a high-carbohydrate, low-fat diet to intact animals.
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PMID:Pyruvate stimulates hormonal induction of lipogenic enzymes in primary cultured rat hepatocytes. 821 43

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


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