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)

The activities of several glycolytic enzymes (hexokinase, phosphofructokinase, pyruvate kinase, lactate dehydrogenase) as well as glycerol-1-phosphate dehydrogenase and (Mg2+)ATPase in normal cerebrospinal fluid (CSF) and blood plasma samples, from 12 healthy infants, aged 2-18 months, and in supernatants from brain tissue slices, taken during neurosurgical operations from infants of the same range of age were estimated. The values obtained confirm the high activity of the above enzymes found in animal brains, and indicate an independence of these activities in blood plasma and CSF. The origin of the activities of the investigated enzymes in CSF seems to be mainly, if not, exclusively, from brain tissue. This might be useful for detection of brain tissue damage as was earlier proven with LDH activity in CSF.
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PMID:Some glycolytic enzymes in normal cerebrospinal fluid, brain tissue and blood plasma of infants. 13 54

The activity of the erythrocyte enzymes: glucose-6-phosphate dehydrogenase, pyruvate kinase, glutathion reductase and ATPase were measured in 8 patients with untreated myelomatosis. Glucose-6-phosphate dehydrogenase was significantly increased. Glucose-6-phosphate dehydrogenase values were negatively correlated with the glomerular filtration rate as measured by 51Cr-EDTA clearance. The results support the existence of a shortened red cell survival in peripheral blood related to the degree of renal insufficiency.
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PMID:Erythrocyte enzymes in myelomatosis. 13 47

The characteristics of the glycolytic pathway and the plasma membrane of Lactobacillus and Bifidobacterium were studied. The enzyme system of glycolysis (hexokinase, glucokinase and pyruvate kinase) which is the main source of energy in the anaerobic condition was localized in the cell soluble fraction (cytoplasma) of all species examined. Neither electron transfer chain components nor oxidase activities were found in anaerobically cultured Lactobacillus and Bifidobacterium. Adenosine triphosphatase (ATPase) activities were mainly localized in the plasma membrane, suggesting that membrane ATPase is playing a key role in membrane transport and ATP synthesis of anaerobic bacilla. SDS-polyacrylamide gel electrophoresis of membranes showed remarkable differences between the polypeptides patterns of B. adolescentis and B. bifidum. Such peculiarities in polypeptide patterns among the same genus may be useful in the identification of species.
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PMID:Characterization of the glycolysis pathway and the plasma membrane of Lactobacillus and Bifidobacterium strains. 13 31

1. The myosin content of myofibrils was found to be 51% by SDS-gel electrophoresis. 2. The initial burst of Pi liberation of the ATPase [EC 3.6.1.3] of a solution of myofibrils in 1 M KCl was measured in 0.5 M KCl, and found to be 0.93 mole/mole of myosin. 3. The amount of ADP bound to myofibrils during the ATPase reaction and the ATPase activity were measured by coupling the myofibrillar ATPase reaction with sufficient amounts of pyruvate kinase [EC 2.7.1.40] and PEP to regenerate ATP. The maximum amount of ADP bound to myofibrils in 0.05M KCl and in the relaxed state was about 1.5 mole/mole of myosin. On the other hand, the ATPase activity exhibited substrate inhibition, and the amount of ATP required for a constant level of ATPase activity was smaller than that required for the maximum binding of ADP to myofibrils. 4. The maximum amount of ADP bound to myofibrils in 0.5 M KCl was about 1.9 mole/mole of myosin. When about one mole of ADP was found to 1 mole of myosin in myofibrils, the myofibrillar ATPase activity reached the saturated level, and with further increase in the concentration of ATP one more mole of ADP was found per mole of myosin.
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PMID:Structure and function of the two heads of the myosin molecule. I. Binding of adenosine diphosphate to myofibrils during the adenosinetriphosphatase reaction. 13 77

F-Actin (FA) and pyruvate kinase (PK) [EC 2.7.1.40] were immobilized on PAB-cellulose. HMM-Subfragment-1 (S-1) was applied to a column of immobilized FA and PK, and eluted with 1-1.5 muM ATP and 1 mM PEP in 50 mM KCl, 2 mM MgCl2, and 10 mM Tris-HCl at pH 7.8 and 4 degrees. The size of the initial burst of Pi liberation of S-1 applied to the column was 0.5 mole/mole S-1. The burst size of S-1 decreased with increase in the fraction number, and S-1 in later fractions showed a burst size of 0.1-0.3 mole/mole. On the other hand, the rate of the ATPase [EC 3.6.1.3] reaction in the steady state was almost independent of the burst size, and increased slightly with increase in the fraction number. The ATPase activity of S-1 with a burst size of less than 0.2 mole/mole was scarcely activated by FA. Usually, the dependence on the burst size of S-1 of its ATPase activity in the presence of FA was sigmoidal, and marked activation by FA was observed when the burst size was larger than 0.3-0.4 mole/mole. Similar results were obtained with S-1 fractions separated by the ultracentrifugation method described in our previous paper ((1976) J. Biochem. 79, 419-434).
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PMID:Structure and function of the two heads of the myosin molecule. II. Separation of the two fractions of subfragment-1 of myosin by affinity column chromatography on immobilized F-actin: direct evidence for acceleration by F-actin of the decomposition of the reactive enzyme-phosphate-ADP complex formed on head B of myosin. 13 78

Juvenile rats fed a diet containing 1% lead acetate for 7 weeks, in addition to an impaired growth rate and renal function derangements, suffered malabsorption of glucose and certain amino acids, as assessed by an in vivo perfusion technique. The reduction in glucose absorption ranged between 10% and 31% when the carbohydrate was pumped in concentrations of 2-80 mM. This alteration was compatible with a noncompetitive type of transport inhibition. The intestinal absorption of glycine, lysine, and phenylalanine were, respectively, decreased 22, 18, and 15% when these amino acids were present at 1 mM levels. Sodium transport was severely reduced (57.6 +/- 17.9 (SEM) vs. 124.2 +/- 17.4 muEq/min-cm) and intestinal mucosa (Na+-K+)-ATPase was concomitantly lower in the lead-intoxicated rats (186.4 +/- 19.0 vs 268.4 +/- 29.8 nmol P/min-mg protein). However, this enzyme was not altered in liver and kidney. Furthermore, intestinal mucosa fructose-1,6-diphosphatase, succinic dehydrogenase, pyruvate kinase, and tryptophan hydroxylase were not different in experimental and control animals. These studies substantiate the presence of functional and biochemical abnormalities in the intestinal mucosa of young rats when fed substantial amounts of a soluble lead salt. It is, therefore, reasonable to accept the possibility that physiologic damage occurs in tissues directly subjected to high and persistent levels of a toxic agents, as it occurs in other organs, underscoring the parallelism between transport mechanisms at the renal and intestinal levels.
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PMID:Experimental lead poisoning and intestinal transport of glucose, amino acids, and sodium. 13 38

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

The patterns of survival of isotope-labelled erythrocytes were examined in patients suffering from two variants of congenital non-spherocytic haemolytic anaemia with decreased erythrocyte pyruvate kinase (PK) activity. In one variant, with primary PK defect (PPKD) random destruction of erythrocytes was predominant in the process of haemolysis. In the second variant, with primary magnesium activated adenosine triphosphatase (ATP-ase) (Mg++) deficiency and a secondary decrease in PK activity, erythrocytes were destroyed by senescence. Two subpopulations of labelled erythrocytes with different destruction rates were observed in all patients examined, except one with the second variant, with very mild haemolysis. Splenectomy, performed on two patient, was successful only in the variant with PPKD.
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PMID:Congenital non-spherocytic haemolytic anaemia variants with primary and secondary pyruvate kinase deficiency. I. Erythrokinetic patterns. 15 42

Some metabolic effects associated with defective pyruvate kinase (PK) in two variants of congenital non-spherocytic haemolytic anaemia with primary PK and primary adenosine triphosphatase (ATP-ase) (Mg++) deficiency respectively we compared. In one patient with a low erythrocyte ATP level, decreased PK activity appeared together with the irreversible loss of its sensitivity to fructose-I,6-diphosphate (FDP), independently of the experimental conditions. In the second patient, the decrease in PK activity associated with an elevated erythrocyte ATP level was a secondary effect, due to primary ATP-ase (Mg++) deficiency. Removal of excessive amounts of ATP, by dialysis of haemolysates or their in-vitro treatment with ATP-ase, increased PK activity to the normal range and restored its sensitivity to the stimulatory effect of FDP. Similar effects could be obtained after i.v. administration of magnesium laevulinate. Under these in vivo conditions the ATP level was normalized after a transient rise ATP-ase activity, the PK activity increased and its sensitivity to FDP reappeared.
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PMID:Congenital non-spherocytic haemolytic anaemia variants with primary and secondary pyruvate kinase deficiency. II. Enzymatic studies. 15 43

The purpose of the present study was to investigate the interactions between ATP, ADP and calcium binding by rat heart sarcoplasmic reticulum vesicles (SR), and to re-evaluate the assay method used to study calcium binding. Calcium binding or transport was studied by the Millipore filtration method. Rat heart SR has an unusually high Mg2+ stimulated ATPase activity (1.37 +/- 0.16 mumol Pi per min per mg at 25 degrees C) so that previous incubation with ATP in calcium binding studies releases ADP and Pi. By maintaining ATP at high and ADP at low concentrations with an ATP-regenerating system (phosphoenolpyruvate and pyruvate kinase), calcium binding capacity was increased by two to three times that of a non-ATP-regenerating system and there was a direct relationship between the amount of Ca-binding and SR protein concentration. When Ca2+ and Mg2+ concentrations were controlled and ATP and ADP concentrations were varied independently the initial rate of Ca-binding was inhibited 25% by 1 mmol.litre-1 ADP and 48% by 3mmol.litre-1 ADP. ATP limited the initial rate of Ca-binding only at ATP levels below 2mmol.litre-1. At low ATP concentrations Ca-release was observed. However, in the presence of an ATP-regenerating system no Ca-release was observed, even at low concentrations of ATP. This study shows that ADP is an inhibitor of Ca-binding by rat heart SR. However, the possibility that high ADP concentrations in the presence of Pi from ATP hydrolysis, could facilitate calcium release cannot be excluded. In addition to the possible physiological importance, these effects must be regarded when assaying rat cardiac SR calcium binding.
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PMID:Effects of adenine nucleotides on calcium binding by rat heart sarcoplasmic reticulum. 15 12


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