Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
 6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Male Wistar rats were given a single i.v. injection of lead nitrate (10 mumol/100 g body wt) and were killed with matched controls 24, 48, 72 h and 20 days after the treatment. Changes of liver carbohydrate metabolism were studied histochemically testing the following parameters: glycogen content, activities of glycogen synthase (SYN), glycogen phosphorylase (PHO), glucose-6-phosphatase (G6PASE), glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH), glyceraldehyde-3-phosphate dehydrogenase (GAPDH). In addition, gammaglutamyltransferase (GGT) activity was demonstrated. Between 24 and 48 h after lead nitrate injection there was a nearly complete loss of liver glycogen. Seventy-two hours later the polysaccharide reappeared in single hepatocytes and after 20 days the livers of the lead-treated animals not only had replenished their glycogen stores but contained even more glycogen than the matched controls. SYN and PHO activities were diminished from 24 to 72 h, but returned to control values after 20 days. G6PASE and GGT remained elevated up to 72 h before dropping to normal at 20 days after treatment. The pentose phosphate pathway enzymes G6PDH and 6PGDH showed the most remarkable changes in livers treated with lead nitrate. G6PDH was already elevated at 24 h, but only in Kupffer cells. At 48 and 72 h, when hepatocytes exhibited a highly increased mitotic rate, the levels of G6PDH, 6PGDH and GAPDH were elevated. After 20 days dehydrogenase activities were comparable to those of controls. The results of this study suggest that a single dose of lead nitrate not only stimulates proliferation of hepatocytes but also induces considerable changes in rat liver carbohydrate metabolism, especially between 24 and 72 h after administration. During that period glycogen metabolism undergoes a strong reduction, whereas gluconeogenesis and particularly the pentose phosphate pathway respond with a remarkable increase. This metabolic profile is most likely associated with lead biotransformation as well as with liver cell proliferation. It corresponds only partially to that found in preneoplastic and neoplastic liver lesions observed in chemical carcinogenesis, and is reversible, in contrast to the persistent alterations associated with neoplastic transformation.
 ...
PMID:Effect of lead nitrate on liver carbohydrate enzymes and glycogen content in the rat. 217 37

The activities of 6 enzymes involved in carbohydrate metabolism were determined quantitatively in preovulatory oocytes by cytochemical means per individual cell as well as biochemically in cell homogenates. Oocytes were incorporated in a polyacrylamide matrix for appropriate enzyme cytochemical staining. This incorporation preserves the morphology of the cells very well, and the enzymes keep their activity for a considerable period of time. This method could also be used to demonstrate more than one enzyme activity in the same cell. The results obtained by cytochemical means appeared to correlate very well with the biochemical data (P less than 0.005). Glucose 6-phosphate dehydrogenase, the key-enzyme in the pentose phosphate pathway, had very high activity in these preovulatory oocytes, but 6-phosphogluconate dehydrogenase activity was only about 2% of that of glucose 6-phosphate dehydrogenase. The activities of lactate dehydrogenase and to a lesser extent glucose phosphate isomerase and D-glyceraldehyde-3-phosphate dehydrogenase also appeared to be very high, while hexokinase showed a very low activity.
 ...
PMID:A cytochemical method for measuring enzyme activity in individual preovulatory mouse oocytes. 241

The specific activities of each of the enzymes of the classical pentose phosphate pathway have been determined in both cultured procyclic and bloodstream forms of Trypanosoma brucei. Both forms contained glucose-6-phosphate dehydrogenase (EC 1.1.1.49), 6-phosphogluconolactonase (EC 3.1.1.31), 6-phosphogluconate dehydrogenase (EC 1.1.1.44), ribose-5-phosphate isomerase (EC 5.3.1.6) and transaldolase (EC 2.2.1.2). However, ribulose-5-phosphate 3'-epimerase (EC 5.1.3.1) and transketolase (EC 2.2.1.1) activities were detectable only in procyclic forms. These results clearly demonstrate that both forms of T. brucei can metabolize glucose via the oxidative segment of the classical pentose phosphate pathway in order to produce D-ribose-5-phosphate for the synthesis of nucleic acids and reduced NADP for other synthetic reactions. However, only procyclic forms are capable of using the non-oxidative segment of the classical pentose phosphate pathway to cycle carbon between pentose and hexose phosphates in order to produce D-glyceraldehyde 3-phosphate as a net product of the pathway. Both forms lack the key gluconeogenic enzyme, fructose-bisphosphatase (EC 3.1.3.11). Consequently, neither form should be able to engage in gluconeogenesis nor should procyclic forms be able to return any of the glyceraldehyde 3-phosphate produced in the pentose phosphate pathway to glucose 6-phosphate. This last specific metabolic arrangement and the restriction of all but the terminal steps of glycolysis to the glycosome may be the observations required to explain the presence of distinct cytosolic and glycosomal isoenzymes of glyceraldehyde-3-phosphate dehydrogenase and phosphoglycerate kinase. These same observations also may provide the basis for explaining the presence of cytosolic hexokinase and phosphoglucose isomerase without the presence of any cytosolic phosphofructokinase activity. The key enzymes of the Entner-Doudoroff pathway, 6-phosphogluconate dehydratase (EC 4.2.1.12) and 2-keto-3-deoxy-6-phosphogluconate aldolase (EC 4.1.2.14) were not detected in either procyclic or bloodstream forms of T. brucei.
 ...
PMID:The enzymes of the classical pentose phosphate pathway display differential activities in procyclic and bloodstream forms of Trypanosoma brucei. 292 7

The influence of prolactin (Prl) and bromocriptine on the specific activities of neural and glial cellular enzymes involved in carbohydrate metabolism in cerebral cortex, hypothalamus, cerebellum and pons-medulla was studied. Both Prl and bromocriptine stimulated the activity of hexokinase (HK) in the neural as well as in the glial cells. While Prl increased the activity of phosphofructokinase (PFK), glyceraldehyde-3-phosphate dehydrogenase (G-3-PDH) and pyruvate kinase (PK) in the neural cells, it decreased the same in the glial cells. On the other hand, bromocriptine elevated the activity of all these enzymes in the neural cells without any effect on the glial cells. The activities of neural cellular glucose-6-phosphate dehydrogenase (G-6-PDH) and 6-phosphogluconate dehydrogenase (6-PGDH) were inhibited by Prl, whereas bromocriptine increased the same. The activities of these enzymes in the glial cells were enhanced by both Prl and bromocriptine. Thus, the present study suggests that Prl has a differential effect on the activities of enzymes involved in Embden-Meyerhoff pathway (EMP) and hexosemonophosphate shunt (HMP) in the neural and glial cells of immature male bonnet monkeys.
 ...
PMID:Role of prolactin on neural and glial cellular enzymes involved in carbohydrate metabolism. I. Studies on immature male bonnet monkeys. 340 16

Thirty-six biopsy specimens of human biceps and vastus lateralis muscles were examined by histometric analysis and determination of enzyme activities (phosphorylase, triosephosphate dehydrogenase, 3-hydroxacyl-CoA-dehydrogenase, lactate dehydrogenase, hexose isomerase, citrate synthetase, 6-phosphogluconate dehydrogenase). The series included 13 specimens from patients suffering from a benign form of muscular dystrophy (limb girdle and Becker type of muscular dystrophy) and 12 specimens from patients with an acute (n = 5) or chronic (n = 7) form of myositis. Muscle fibres were atrophic in myositis and hypertrophic (with an increased variation of fibre diameters) in muscular dystrophies, as has been shown previously. When myositis samples were compared with either normal or dystrophic muscles, a highly significant lowering of glycolytic enzyme activity was found in chronic myositis, while the activity of 6-phosphogluconate dehydrogenase was elevated to highly significant levels. Measurements of the latter enzyme's activity might be of additional value in differentiating chronic forms of myositis from benign muscular dystrophies.
 ...
PMID:Additional biochemical criteria in the differential diagnosis of myositis. 343 Jan 87

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.
 ...
PMID:[Demonstration of an NAD-dependent 6-phosphogluconate dehydrogenase in Pseudomonas syringae pv. phaseolicola]. 362 76

Glucose-6-phosphate dehydrogenase (G6PDH), 6-phosphogluconate dehydrogenase (6PGDH) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activities were assayed in superficial pectoral muscles of hereditary dystrophic chickens, 1 week, 2 weeks, 4 weeks and 4 months after hatching. In control chickens, activities of G6PDH and 6PGDH were very low at 4 months of age; however, at 1 week of age, they were much higher than those at 4 months of age. Activities of G6PDH and 6PGDH were significantly higher in dystrophic chickens compared with those in the controls at all the stages of development studied. These findings suggest that considerable activities of G6PDH and 6PGDH are present within the pectoral muscle cells at early stages of development, at least in dystrophic chickens. GAPDH activity was significantly lower in dystrophic chickens at 2 weeks, 4 weeks and 4 months of age compared with those in control chicken. These findings together with our previous studies (Mizuno 1984a,b) in which increased activities of superoxide dismutases, catalase, glutathione peroxidase and glutathione reductase were reported in dystrophic chickens, indicate the presence of an increased capacity for the turnover of oxygen-free radicals within muscle cells in dystrophic chickens, and that oxygen-free radicals and the related activated oxygen species may be playing a role in inducing cellular damage.
 ...
PMID:Glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glyceraldehyde-3-phosphate dehydrogenase activities in early stages of development in dystrophic chickens. 398 80

Crude extracts of both vegetative cells and glycerol-induced microcysts of Myxococcus xanthus contained the following enzyme activities: phosphofructokinase, phosphoglucoisomerase, fructose-1,6-diphosphatase, fructosediphosphate aldolase, glyceraldehyde-3-phosphate dehydrogenase, phosphopyruvate carboxylase, citrate synthase, isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, phosphoglucomutase, and uridine diphosphate glucose pyrophosphorylase. With the exception of isocitrate dehydrogenase, which was present at a fivefold higher concentration in microcysts, all activities in extracts from both types of cells were essentially equal. Hexokinase and pyruvate kinase could not be detected in extracts from either type of cell. Microcysts metabolized acetate at a lower rate than did vegetative cells. Most of this decrease was reflected in a substantial decrease in ability of microcysts to oxidize acetate to CO(2). In addition, microcysts and vegetative cells showed a different distribution of (14)C-label from incorporated acetate.
 ...
PMID:Comparative intermediary metabolism of vegetative cells and microcysts of Myxococcus xanthus. 430 96

A summary of a survey of three genera of mycoplasmatales (Mycoplasma, Acholeplasma, and Ureaplasma) for isozyme expression is presented. Isozyme analysis of mycoplasmas has been employed in at least three distinct areas: (1) as genetic markers for identification, individualization, and taxonomic classification; (2) as markers for cell culture contamination; and (3) as a qualitative measure of the operative metabolic pathways in the diverse species. We have found five ubiquitous enzymes: purine nucleoside phosphorylase, adenylate kinase, inorganic pyrophosphatase, dipeptidase, and esterase. Three enzymes, glucose-6-phosphate dehydrogenase, phosphogluconate dehydrogenase, and superoxide dismutase, were restricted to Acholeplasma species and were not detected in Mycoplasma or Ureaplasma. Four glycolytic enzymes, glucose phosphate isomerase, triose phosphate isomerase, glyceraldehyde-3-phosphate dehydrogenase, and lactate dehydrogenase, were restricted to those species of Mycoplasma and Acholeplasma capable of glucose fermentation. Two of these glycolytic enzymes, glucose phosphate isomerase and lactate dehydrogenase, were detected in serovars I and II of U. urealyticum, which is inconsistent with the non-glycolytic activity in this genus.
 ...
PMID:On the distribution and characteristics of isozyme expression in Mycoplasma, Acholeplasma, and Ureaplasma species. 667 51

A new procedure for the activity measurement of NAD(P)+-dependent dehydrogenases has been devised using an electron-transferring agent, phenazine methosulfate, and an electron acceptor, 3-(4,5-dimethylthiazolyl)-2,5-diphenyltetrazolium bromide. The reduction of the latter is determined by an increase in absorbance at 578 nm. 3-Iodopyridineadenine dinucleotide was found to be active as an hydride acceptor with horse liver alcohol dehydrogenase and lactate dehydrogenase but showed no activity with glyceraldehyde-3-phosphate dehydrogenase nor did its phosphate with 3-phosphogluconate dehydrogenase.
 ...
PMID:Activity determination of 3-iodopyridineadenine dinucleotide and its phosphate as hydride acceptors in the presence of dehydrogenases using a coupled redox system. 700 42


<< Previous 1 2 3 4 5 Next >>