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:3.6.1.3 (ATPase)
65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Administration of 60,000 i.e. of vitamin A into rats within three weeks caused an increase in amount of reticulocytes, in the rate of glucose utilization and in formation of lactic acid by erythrocytes. The activity of glycolytic enzymes was intensified. The activity of hexokinase was increased by 84.6%, activities of aldolase and phosphohexoisomerase were increased by 34%. But in the erythrocytes content of AMP, ADP and ATP was unaltered, probably due to activation of total and Na+, K+-dependent ATPase. The harmful effect of an excess of the vitamin A was manifested in an increased content of Na+ in erythrocytes and also in decreased stability of the cells to acid hemolytics.
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PMID:[Intensity of glycolysis and energy metabolism in erythrocytes in experimental hypervitaminosis A]. 13 57

ATPase activity of actomyosin and activity of glycogenolytic enzymes were distinctly increased during postnatal period of development. Direct correlation was observed between the actomyosin ATPase and phosphofructokinase, phosphohexoisomerase, enolase, pyruvate kinase, lactate dehydrogenase and "bound" fraction of aldolase. Kinetic patterns of phosphofructokinase (Km and Hill's coefficient) were not altered at the postnatal period. Formation of complexes between the contractile proteins and glycolytic enzymes appears to be important in development of contractile function.
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PMID:[Comparative study of the changes in the ATPase activity of actomyosin and in the activity of skeletal muscle glycolytic enzymes in the early postnatal period of development]. 14 21

Several glycolytic enzymes were observed to have between 40-90% of their activities associated with the particulate fractions of lysed nerve endings. The enzymes showing high particulate activity in lysed nerve endings were hexokinase (EC 2.7.1.1), aldolase (EC 4.1.2.13), glucosephosphate isomerase (EC 5.3.1.9), phosphofructokinase (EC 2.7.1.11), glyceraldehyde-phosphate dehydrogenase (EC 1.2.1.12), pyruvate kinase (EC 2.7.1.40) and lactate dehydrogenase (EC 1.1.27). With the exception of phosphofructokinase, 80% or more of the particle associated activity of each enzyme was solubilized by salt treatment indicating the association with particles was ionic. Sub-fractionation of lysed nerve endings showed hexokinase and fumarase (EC 4.2.1.2) had the highest specific activity in the same fractions which is consistent with observations indicating that hexokinase is associated with mitochondria. The other glycolytic zymes having high particulate activity, aldolase, glucosephosphate isomerase, phosphofructokinase, glyceraldehyde-phosphate dehydrogenase, pyruvate kinase and lactate dehydrogenase, showed enrichment in fractions containing synaptosomal membranes, i.e. the fractions having highest specific activity of acetylcholinesterase (EC 3.1.1.7) and (Na+ + K+)-ATPase (EC 3.6.1.3).
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PMID:Association of glycolytic enzymes with particulate fractions from nerve endings. 62 35

Selected enzymes of energy metabolism were measured in random individual fibers of soleus and tibialis anterior (TA) muscles from rats exposed for 2 wk to spaceflight (F) aboard COSMOS 2044 or tail suspension (T) and from synchronous controls. Average size of soleus fibers (dry weight per unit length) was reduced 37% in F and T fibers; there was little change in TA fibers. Enzyme changes were more pronounced in soleus than in TA fibers. Three enzymes characteristic of fast-twitch muscles, pyruvate kinase, glycerol-3-phosphate dehydrogenase, and 1-phosphofructokinase, were elevated in F and T soleus fibers, but changes in phosphofructokinase were not statistically significant. 3-Ketoacid-CoA transferase, characteristic of slow-twitch muscles, did not change significantly in either F or T fibers. Hexokinase, usually moderately higher in slow- than in fast-twitch muscles, increased markedly in both F and T fibers. In TA fibers analyzed for hexokinase, malate dehydrogenase, phosphohexoisomerase, and pyruvate kinase, only hexokinase and malate dehydrogenase showed significant changes. Hexokinase increased 83% in one of two T muscles. Enzyme data for TA fibers typed by myosin adenosinetriphosphatase were more informative: phosphofructokinase, phosphorylase, and glycerol-3-phosphate dehydrogenase were increased in type IIb fibers of either F or T muscles or both. Malate dehydrogenase was not changed in fibers of any type in either F or T muscle.
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PMID:Effects of microgravity and tail suspension on enzymes of individual soleus and tibialis anterior fibers. 138 50

One hundred and five sexually mature male hamsters were divided in different groups. In the first experiment hamsters were administered gossypol, 10 mg/kg and 20 mg/kg/body weight/day, for twenty and thirty days. In the second experiment hamsters were administered gossypol, 5, 10 and 20 mg/kg/body weight/day, for sixty days. In the third experiment, hamsters were administered gossypol 5 mg, 10 mg, 20 mg and 40 mg/kg body weight/day for 45 days. Animals in all the groups were given gossypol by oral intubation every day. No significant effect on the body weight of hamsters following gossypol treatment was observed. At low doses the weights of testis and accessory sex organs were not statistically different from those of the controls. A significant decrease in testis and epididymis weight was however observed following high doses of gossypol. Low doses of gossypol treatment did not affect the motility of the vas deferens spermatozoa. The vas deferens spermatozoa were however immotile after 40 mg/kg/day gossypol treatment. Gossypol treatment induced a series of histological changes in the seminiferous epithelium of the hamster testis. The earliest sign of drug effect was seen in spermatids and with the increase in doses the effects became more pronounced and extended to the spermatocytes. At 40 mg/kg dose an almost complete arrest of spermatogenesis was observed. Quantitatively, the ratio of pachytene spermatocytes: resting spermatocytes and step 7 spermatids: pachytene spermatocytes decreased significantly. The step 7 spermatids did not mature to step 19 spermatids at all. Histochemically activities of ATPase, SDH and LDH decreased with the increasing doses of gossypol, the activity of 3B hydroxysteroid dehydrogenase was not affected by gossypol treatment. In testis the glucose-6-phosphatase activity was not affected significantly but the activities of fructose 1, 6-diphosphatase and glucose-6-phosphate isomerase decreased significantly with the increasing doses of gossypol. Amylase activity rose significantly at higher doses. Marked changes in LDH and LDH-X were however observed with the increase in gossypol dose. In liver the activity of glucose-6-phosphatase increased significantly while the activities of fructose 1, 6-diphosphatase, glucose-6-phosphate isomerase and amylase were not affected following gossypol treatment. The glycogen contents however increased significantly following high doses of gossypol. No changes in testosterone production and plasma levels of testosterone were observed following gossypol treatment.
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PMID:Response of hamster to the antifertility effect of gossypol. 170 27

Addition of glucose or fructose to cells of Saccharomyces cerevisiae adapted to grow in the absence of glucose induced an acidification of the intracellular medium. This acidification appeared to be due to the phosphorylation of the sugar since: (i) glucose analogues which are not efficiently phosphorylated did not induce internal acidification; (ii) glucose addition did not cause internal acidification in a mutant deficient in all the three sugar-phosphorylating enzymes; (iii) fructose did not affect the intracellular pH in a double mutant having only glucokinase activity; (iv) glucose was as effective as fructose in inducing the internal pH drop in a mutant deficient in phosphoglucose isomerase activity; and (v) in strains deficient in two of the three sugar-phosphorylating activities, there was a good correlation between the specific glucose- or fructose-phosphorylating activity of cell extracts and the sugar-induced internal acidification. In addition, in whole cells any of the three yeast sugar kinases were capable of mediating the internal acidification described. Glucose-induced internal acidification was observed even when yeast cells were suspended in growth medium and in cells suspended in buffer containing K+, which supports the possible signalling function of the glucose-induced internal acidification. Evaluation of internal pH by following fluorescence changes of fluorescein-loaded cells indicated that the change in intracellular pH occurred immediately after addition of sugar. The apparent Km for glucose in this process was 2 mM. Changes in both the internal and external pH were determined and it was found that the internal acidification induced by glucose was followed by a partial alkalinization coincident with the initiation of H+ efflux. This reversal of acidification could be due to the activity of the H+-ATPase, since it was inhibited by diethylstilboestrol. Coincidence between internal alkalinization and the H+ efflux was also observed after addition of ethanol.
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PMID:The mechanism of intracellular acidification induced by glucose in Saccharomyces cerevisiae. 269 47

Zinc, lead and cadmium in the form of chloride salts when added to a standard assay system containing 80 X 10(-6) ejaculated washed human spermatozoa caused a dose and duration-dependent inhibition of their motility. The activity of certain key enzymes of carbohydrate and energy metabolism, viz, glycogen phosphorylase, glucose-6-phosphatase, fructose-1, 6-diphosphatase, glucose-6-phosphate isomerase, amylase, Mg2+- dependent ATPase and lactic and succinic acid dehydrogenases were also found to be inhibited. The order of inhibitory effects of the heavy metals were zinc less than lead less than cadmium. The metal chelating agent, ethylene diamine tetra-acetic acid (EDTA, disodium salt) also interfered with the spermatozoal motility and inhibited the enzyme activities.
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PMID:Effect of selected metal ions on the motility and carbohydrate metabolism of ejaculated human spermatozoa. 314 74

Glycosomes and mitochondrial vesicles from cultured promastigotes of Leishmania mexicana mexicana have been separated using isopycnic centrifugation on linear sucrose gradients. Hexokinase (EC 2.7.1.2), glucose phosphate isomerase (EC 5.3.1.9), phosphofructokinase (EC 2.7.1.11), glyceraldehyde-3-phosphate dehydrogenase (EC 1.2.1.12), and phosphoenolpyruvate carboxykinase (EC 4.1.1.49) were recovered largely in association with glycosomes (density; 1.215 g/ml). Phosphoglycerate kinase (EC 2.7.2.3) and glucose-6-phosphate dehydrogenase (EC 1.1.1.49) had some small glycosomal activity, but were mostly recovered in the soluble fractions. Malate dehydrogenase (EC 1.1.1.37) showed a broad peak corresponding to that of the mitochondrial marker oligomycin-sensitive ATPase (EC 3.6.1.4) (density; 1.190 g/ml). Glutamate dehydrogenase (EC 1.4.1.3) and alanine aminotransferase (EC 2.6.1.2) both showed small mitochondrial peaks, but most of the activities were recovered elsewhere on the gradient and in the soluble fractions. The subcellular location of enzymes in L.m. mexicana amastigotes was investigated by following the release of soluble enzymes from digitonin-treated amastigotes. This revealed distinct cytosolic, mitochondrial, and glycosomal compartments. The findings give an insight into the organization and control of L.m. mexicana promastigote and amastigote energy metabolism.
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PMID:Leishmania mexicana: subcellular distribution of enzymes in amastigotes and promastigotes. 315 38

1. Intracellular concentrations of intermediates and cofactors of glycolysis were measured in guinea-pig cerebral cortex slices incubated under varying conditions. 2. Comparison of mass-action ratios with apparent equilibrium constants for the reactions of glycolysis showed that hexokinase, phosphofructokinase and pyruvate kinase catalyse reactions generally far from equilibrium, whereas phosphoglucose isomerase, aldolase, phosphoglycerate kinase, phosphoglycerate mutase, enolase, adenlyate kinase and creatine phosphokinase are generally close to equilibrium. The possibility that glyceraldehyde 3-phosphate dehydrogenase may catalyse a ;non-equilibrium' reaction is discussed. 3. Correlation of changes in concentrations of substrates for enzymes catalysing ;non-equilibrium' reactions with changes in rates of glycolysis caused by alteration of the conditions of incubation showed that hexokinase, phosphofructokinase, pyruvate kinase and possibly glyceraldehyde 3-phosphate dehydrogenase are subject to metabolic control in cerebral cortex slices. 4. It is suggested that the glycolysis is controlled by two regulatory systems, the hexokinase-phosphofructokinase system and the glyceraldehyde 3-phosphate dehydrogenase-pyruvate kinase system. These are discussed. 5. It is concluded that the rate of glycolysis in guinea-pig cerebral cortex slices is limited either by the rate of glucose entry into the slices or by the hexokinase-phosphofructokinase system. 6. It is concluded that addition of 0.1mm-ouabain to guinea-pig cerebral cortex slices causes inhibition of either glyceraldehyde 3-phosphate dehydrogenase or phosphoglycerate kinase or both, in a manner independent of the known action of ouabain on the sodium- and potassium-activated adenosine triphosphatase.
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PMID:Control of glycolysis in cerebral cortex slices. 422 84

1. Methods of homogenizing suspensions of washed mammalian spermatozoa were studied. The most useful methods were those using sonication and those using a French press. 2. Hexokinase, phosphofructokinase, glucose phosphate isomerase and adenosine triphosphatase activities in ram, bull and boar spermatozoa were investigated by using these two homogenization methods. Glucose phosphate isomerase, representative of soluble cytoplasmic material, was very readily extracted and remained entirely in the supernatant after centrifugation at 145000g for 60min. In contrast, the other three activities were less easily extracted and were sedimented in various proportions under the described conditions of centrifugation. 3. Attempts to obtain subcellular fractions from sperm homogenates by ;classical' methods failed, owing apparently to the inhomogeneity of subcellular particles in the homogenates. It is concluded that, after removal of sperm heads, the only meaningful fractionation is a separation of spermatozoal material which sediments at 145000g during 60min from that which does not. 4. The stabilities of hexokinase and phosphofructokinase activities in bull, boar and ram sperm homogenates were investigated. Hexokinases showed very little dependence on the various environments tested, whereas the optimum conditions for phosphofructokinase stability were: a minimum of sonication, the presence of phosphate ions and of a thiol-group protectant, and a pH7.5. Activities of hexokinase, phosphofructokinase and glucose phosphate isomerase per sperm cell were compared with published data on rates of fructolysis by spermatozoa; the potential catalytic activities were shown to be considerably in excess of these rates. However, phosphofructokinase may be the rate-limiting enzyme of glycolysis in vivo in bull and ram spermatozoa.
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PMID:Glycolytic enzymes in mammalian spermatozoa. Activities and stabilities of hexokinase and phosphofructokinase in various fractions from sperm homogenates. 425 94


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