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:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Crude extracts from cells of Pseudomonas syringae pv. phaseolicola, a fluorescent pseudomonad, when grown on glucose contain a NAD-linked 6-phosphogluconate dehydrogenase. The reaction of the enzyme, which produces 14CO2 from 1-14C-6-phosphogluconate, is not inhibited by NaF, a potent inhibitor of the Enter-Doudoroff (ED) pathway enzyme 6-phosphogluconate dehydratase. In the presence of phosphate or arsenate ions the NAD-linked glyceraldehyde-3-phosphate dehydrogenase reacts with glyceraldehyde-3-phosphate which, in the ED pathway, is produced from 6-phosphogluconate and overlaps the 6-phosphogluconate dehydrogenase reaction. Only a small proportion of glucose is metabolized via the 6-phosphogluconate dehydrogenase/oxidative pentose phosphate pathway.
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PMID:[Demonstration of an NAD-dependent 6-phosphogluconate dehydrogenase in Pseudomonas syringae pv. phaseolicola]. 362 76

Rat liver transketolase (TK) has been purified, in a single step, by immunoaffinity chromatography on specific TK antibodies covalently linked to Sepharose 4B. The procedure described also involves the raising and isolation of rabbit TK antibodies to the conventionally purified enzyme [F. Paoletti (1983) Arch. Biochem. Biophys. 222, 489-496]. Affinity chromatography allows a 100-fold purification of TK from the cell cytosol and a recovery of about 70% of the original activity. The TK isolated has a specific activity of 2.7-3.2 at 25 degrees C and migrates as a single band on polyacrylamide gel electrophoresis at pH 9.1. Multiple forms of the enzyme, with distinct pI values in the range 7-8, have been detected in purified preparations by means of analytical isoelectric focusing and staining for TK. No addition of either Mg2+ or thiamine pyrophosphate is required for the activity of the enzyme which, in the native form, exhibits a molecular weight of about 139,000. Two moles of thiamine pyrophosphate can be resolved for each mole of enzyme. Affinity TK preparations are virtually free of glyceraldehyde-3-phosphate dehydrogenase, pentose-phosphate epimerase, and isomerase, although slight contamination by phosphohexose isomerase may occur.
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PMID:Immunoaffinity purification of rat liver transketolase: evidence for multiple forms of the enzyme. 394 99

Gluteal muscle specimens were taken from 4 horses. From 1 of the 4 gluteal muscles, serial sections were prepared. Individual muscle fibers were identified and studied, using photomicrographs of sections stained by different enzyme histochemical methods. In specimens in which cytoplasmic soluble enzymes were studied, use was made of the semi-permeable membrane technique to hamper enzyme diffusion into reaction fluids. Enzymes involved in glycogenolysis, glycolysis, the tricarboxylic acid cycle, synthesis of reduced nicotinamide adenine dinucleotide phosphate, the pentose phosphate cycle, the alpha-glycerolphosphate shuttle, the respiratory chain, catabolism, and muscular contraction were studied. Some key enzymes of different metabolic pathways were also included. Each of 3 fiber types identified had distinct features. Type I fibers were characterized by a relatively strong aerobic capacity, compared with type IIA fibers, which were more glycolytic and had strong aerobic and moderate-to-strong anaerobic capacity. Type IIB fibers were characterized by a relatively low aerobic and a relatively high anaerobic capacity, and were glycolytic. Activities of phosphofructokinase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase, and alpha-naphtylesterase (nonspecific esterase) were so markedly different in the 3 fiber types that fiber typing was possible, aided by the demonstration of the activities of these enzymes. In type IIB fibers, the pentose phosphate cycle was more important than in the other fiber types. Except for the unexplained high alpha-naphtylesterase activity in type IIB fibers, catabolic enzymes were not active in healthy equine muscle fibers.
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PMID:Enzyme histochemical features of equine gluteus muscle fibers. 403 4

Enzymes of the reductive pentose phosphate cycle including ribulose-diphosphate carboxylase, ribulose-5-phosphate kinase, ribose-5-phosphate isomerase, aldolase, glyceraldehyde-3-phosphate dehydrogenase and alkaline fructose-1,6-diphos-phatase were shown to be present in autotrophically grown Rhodospirillum rubrum. Enzyme levels were measured in this organism grown photo- and dark heterotrophically as well. Several, but not all, of these enzymes appeared to be under metabolic control, mediated by exogenous carbon and nitrogen compounds. Light had no effect on the presence or levels of any of these enzymes in this photosynthetic bacterium. The enzymes of the tricarboxylic acid cycle and enolase were shown to be present in R. rubrum cultured aerobically, autotrophically, or photoheterotrophically, both in cultures evolving hydrogen and under conditions where hydrogen evolution is not observed. Light had no clearly demonstrable effect on the presence or levels of any of these enzymes.
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PMID:Photosynthesis in Rhodospirillum rubrum. 3. Metabolic control of reductive pentose phosphate and tricarboxylic acid cycle enzymes. 604 59

The livers from a total of 51 Sprague-Dawley rats treated with different doses of N-nitrosomorpholine (80-120 mg/l in the drinking water) for up to 14 weeks together with the livers of 28 control animals were histochemically investigated at the cessation of carcinogenic insult and at varying periods thereafter for their glycogen content, basophilia and activities of various enzymes of carbohydrate metabolism: glycogen synthetase, glycogen phosphorylase, glucose-6-phosphatase, glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase. The enzymatic patterns of normal tissue, preneoplastic and neoplastic lesions were characterized and compared with reference to the morphologically defined stages of tumor development in the liver. The early appearing glycogen storing areas, localized in the peripheral and intermediate lobular regions, did not show significant changes in the histochemically demonstrable activities of the enzymes tested. After cessation of the carcinogen treatment the more pronounced glycogen storage foci which developed within the aforementioned regions of the liver acinus usually showed a reduction in the activities of phosphorylase and glucose-6-phosphatase while the activity of glucose-6-phosphate dehydrogenase, a key enzyme for the pentose phosphate pathway, was increased. The mixed cell foci, neoplastic nodules and tumors which emerged at later stages were characterized by a progressive shift away from glycogen metabolism towards glycolysis and the pentose phosphate pathway, as indicated by an increase in glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase activities. These changes in enzyme pattern are supportive of a developmental sequence leading from glycogen storage foci through mixed cell foci and neoplastic nodules to hepatocellular carcinomas.
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PMID:Correlative histochemistry of some enzymes of carbohydrate metabolism in preneoplastic and neoplastic lesions in the rat liver. 629 53

Systematic studies of the sequence of cellular changes during hepatocarcinogenesis induced predominantly in rats by stop experiments with N-nitrosomorpholine (NNM) led to the following main results and conclusions: The development of hepatocellular tumors is preceded by a multifocal hepatic glycogen storage disease (glycogenosis). Cytomorphological and cytochemical findings suggest a sequence of focal changes leading from clear and acidophilic glycogen storage foci through mixed cell foci and neoplastic nodules to hepatocellular carcinomas. The clear and acidophilic glycogen storage cells persisting after withdrawal of the carcinogen apparently represent a preneoplastic cell population, the neoplastic transformation of which is accompanied by a gradual reduction of glycogen and a concomitant increase in ribosomes (basophilia). The first appearance and frequency of the different liver lesions investigated was shown to depend on the dose of carcinogen administered. With increasing dose of NNM, the number of focal lesions considerably increased, and this was accompanied by an earlier development of mixed and basophilic cell populations. There was no indication of any reversibility of pronounced focal lesions under the experimental conditions chosen. On the contrary, the foci became larger and acquired phenotypic markers closer to neoplasia independent of further action of the carcinogen. Enzyme histochemically, the majority of the pronounced glycogen storage foci showed a reduction in the activities of glycogen phosphorylase and glucose-6-phosphatase while the activity of glucose-6-phosphate dehydrogenase, a key enzyme for the pentose phosphate pathway, was increased. The mixed cell foci, neoplastic nodules and carcinomas which emerged at later stages were characterized by a progressive shift away from glycogen metabolism towards glycolysis and the pentose phosphate pathway. as indicated by an increase in glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase activities. These changes in enzyme pattern are in keeping with a developmental sequence leading from glycogen storage foci through mixed cell foci and neoplastic nodules to hepatocellular carcinomas. Biochemical microanalysis of dissected glycogen storage foci and mixed cell foci revealed that the foci composed exclusively of storage cells contained on an average 100% more glycogen than the normal liver tissue. The overall glycogen content of the mixed cell foci, which were composed of both glycogenotic and glycogen-poor basophilic cells, was not distinguishable from that of normal tissue.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Hepatocellular glycogenosis and related pattern of enzymatic changes during hepatocarcinogenesis. 659 71

1. Activities of several enzymes of glycolysis, glycerolphosphate cycle, TCA-cycle, beta-oxidation and pentose phosphate cycle were determined in pyloric caeca and ovaries of Asterias rubens during the reproductive cycle. 2. In the ovaries activities of CS and LDH were significantly decreased during ovarian stages 3 and 4, and those of GDH and GAPDH during stage 3 and 4, respectively. 3. In the pyloric caeca activities of GAPDH and LDH were lower in stage 4 and that of GDH in stage 3, whereas those of G6PDH and HOAD were increased in stage 3. 4. Changes observed in enzyme activities are discussed in relation to the reproductive cycle and to the multiple function of the pyloric caeca.
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PMID:Changes in the activities of selected enzymes of intermediary metabolism in the pyloric caeca and ovaries of asterias rubens during the annual reproductive cycle. 680 60

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

It has been proposed that highly biosynthetic cells oxidize fatty acids to generate ATP while maintaining high levels of glucose metabolism through the glycolytic and pentose shunt systems to supply biosynthetic intermediates. We investigated the metabolic strategies and substrate for ATP production in the osteoclast. We used in situ quantitative microcytophotometric techniques to determine the maximal activity of the pentose shunt (glucose-6-phosphate dehydrogenase; G6PD), the glycolytic pathway (glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase; G3PD and LDH), fatty acid oxidation (beta-hydroxyacyl dehydrogenase; HOAD), and the Krebs cycle (succinate dehydrogenase; SDH) in human osteoclasts in situ, and related these enzyme activities to the degree of involvement of the cells in resorption. Unlike other highly biosynthetic cells, such as chondrocytes and macrophage polykaryons, osteoclasts associated with bone resorption were deficient in G3PD, LDH, and G6PD activity. However, osteoclasts did demonstrate a capacity for fatty acid oxidation which increased in cells apposed to the bone surface. The lack of significant glycolytic and pentose shunt activity in the osteoclast provides good evidence that resorbing osteoclasts, unlike phagocytosing macrophage polykaryons, have the metabolic characteristics of cells with greatly reduced capabilities of de novo mRNA synthesis but which do maintain high rates of ATP production. The possibility that the loss of glycolytic activity is a prelude to cell death is discussed.
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PMID:Microcytophotometric analysis of human osteoclast metabolism: lack of activity in certain oxidative pathways indicates inability to sustain biosynthesis during resorption. 815 31

Effects of prolactin(Prl), bromocriptine(Br), testosterone propionate (TP), dihydrotestosterone (DHT) and combinations of these androgens with Prl/Br on the maximum catalytic capacities of seminal vesicular enzymes involved in the glycolytic and pentose phosphate pathways in castrated mature monkeys were studied. Castration decreased the activities of all of the enzymes studied such as hexokinase(HK), 6-phosphofructokinase(PFK), glyceraldehyde-3-phosphate dehydrogenase(G3PD), pyruvate kinase(PK), glucose 6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase(6PGD) in the seminal vesicles. Prl restored the activities of all of the enzymes to their normal values except G3PD. TP/DHT maintained all the enzyme activities at the normal tissue intact level. Prl given along with androgens further enhanced the androgen action with regard to all the enzymes activities except G3PD. Br decreased all of the enzymes but Br with androgens maintained all the enzyme activities at the normal level. Castration decreased significantly serum T/DHT titres but Prl did not alter Prl levels. Prl+TP/DHT elevated Prl levels. Br alone decreased serum Prl, T and DHT titres, but Br+TP/DHT decreased only Prl, elevated T and maintained DHT levels. These results suggest that Prl has a direct as well as a synergistic action with androgens on the activities of the enzymes of glycolysis and pentose phosphate pathways in the seminal vesicles of castrated monkeys.
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PMID:Effects of prolactin and androgens on enzymes of carbohydrate metabolism in seminal vesicles of castrated mature bonnet monkeys, Macaca radiata. 827 11


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