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)

Properties of HCO--3-stimulated ATPase from rat heart muscle nuclei were studied. The maximal activity of HCO--3-ATPase was observed at concentration of bicarbonate 25 mM. The enzyme had a pH optimum at pH 8.0-8.5. Bicarbonate stimulated the ATPase activity only in presence of Mg2+, Mn2+ and Zn2+, Co2+, Cd2+ and Ca2+ were ineffective. NaCO3 and Na2SO3 at concentration 30 mM stimulated the nuclear ATPase activity by 20% and 81%, respectively. Anions N3--, scn--, clO--4, and I-- inhibited both Mg2+-ATPase and HCO--3-ATPase. HSO--3 and SO2--4 ions did not affect the nuclear ATPase activity.
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PMID:[Anion-sensitive nuclear ATPase of the rat heart]. 2 54

The activity of ATPase was studied in highly purified rat liver and thymus cell nuclei, HCO3-, CO3(2-) and SO3(2-) stimulated nuclear ATPase in 1.5--2 times. HSO3- did not affect the enzyme activity, and NO3-, J-, ClO4-,F- and SCN- inhibited it. Bicarbonate increased V and decreased Ka for ATP. SCN- inhibited HCO3--ATPase activity non-competitively with respect to HCO3-. Mg2+-ATPase activity did not depend on pH, and HCO3-component of the activity was decreased under alkaline pH. Mg2+, Mn2+ and Co2+ increased the initial ATPase activity and helped its stimulation with HCO3-. Ba2+, Ni2+ and Zn2+ inhibited the ATPase activity, and Ca2+ did not affect it, Nuclear ATPase is sensitive to 2,4-dinitrophenol and DNAase. It is suggested that cell nuclei have their own H+-ATPase differing for some characteristics from mitochondrial H+-ATPase.
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PMID:[Investigation of adenosinetriphosphatase activity of rat liver and thymus cell nuclei]. 3 23

The distribution, histochemical properties and ultrastructural localization of adenosine triphosphate (ATP) hydrolyzing enzymes in the tanycyte ependyma of the third ventricle have been studied in female Wistar rats. Using a calcium-cobalt procedure and a lead capture technique, splitting of ATP could be demonstrated in perikarya and processes of tanycytes in the region of the ventromedial nucleus. The reaction showed no dependence on magnesium or sodium ions, did not occur with other monodi-, and tri-phosphates as substrates, and was inhibited by p-chlormercuribenzoate (PCMB) and sodium fluoride, but not by ouabain. With the calcium-cobalt method the highest intensity of reaction was found at pH 9.4, whereas the lead method gave optimal results at pH 6--8. At the ultrastructural level, the reaction product was found at the outer surface of the plasma membranes of tanycytes and reached its highest concentrations in the region of the region of the apical microvilli; From the findings it is concluded that splitting of ATP in tanycytes is due to a true ATPase. The enzyme might be involved in an active transport of substances by tanycytes.
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PMID:Distribution and properties of an adenosine triphosphatase in the tanycyte ependyma of the IIIrd ventricle of the rat. 6 Mar 13

Three new techniques are described for staining the Langerhans cell in whole mounts of fresh human and guinea pig epidermis. These employ paraphenylenediamine, gold sodium thiomalate and cobalt chloride, respectively, and require appropriate epidermal separation with EDTA, ammonium thiocyanate or sodium bromide. Used in conjunction with a modified adenosine triphosphatase stain, these techniques provide greater capability for observing the Langerhans cell in disease states than can be achieved by any single stain. A combined stain with adenosine triphosphate and gold is also described.
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PMID:New staining techniques for the Langerhans cell. 7 Sep 19

A selective staining of the nucleus of both the cells in an islet (of Langerhans) and the acinar cells could be observed after treatment with bromide-water in an ATPase-medium (calcium-cobalt-method) on a cryostatsection of rat pancreas. Furthermore the behaviour of the other metal ion forming a complex has been tested in place of cobalt salt. As conditioned for the staining reaction the hydrolysis of nucleic acid with oxidation of its base by bromide-water and also the complex formation of Co++ with compounds similar to alloxan, resulted from oxidation were discussed.
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PMID:[The reactive behaviour of the cell nucleus after a pretreatment with a bromide solution and the application of the calcium-cobalt-method for the ATPase evidence (author's transl)]. 7 39

Adenosine triphosphatase enzymatic activity was investigated in human approximatively normal, dysplastic and neoplastic mammary tissue, by three different methods. Staining intensity varied within wide limits; myoepithelial cells and blood vessels showed similar enzymatic activity. Epithelial cells reacted only faintly, or not at all; carcinoma cells were never labelled. Stromal response was highly variable. The calcium-cobalt method of Padykula and Herman gave more intense reactions than the lead-nitrate procedure of Wachstein and Meisel, either in the original form or according to the modifications recommended by Russo and Wells. With the latter method the sharpness of stain deposits on the different structures was markedly enhanced. The functional significance of ATPase activity is discussed.
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PMID:ATPase activity in the breast: a comparison between three methods. 9 Dec 95

In chronic cobalt-induced experimental epilepsy in the cat, there are alterations in behavior, electroencephalograms, and brain sodium, potassium adenosine triphosphatase (Na,K ATPase) activity. The electrographic and enzymatic changes occur both in focus and homotopic cortex, and are time related. The onset of EEG paroxysms consistently precedes increases in Na,K ATPase activity, indicating that the enzymatic change is adaptive. Prophylactic treatment with phenytoin (formerly diphenylhydantoin) prevents these chronic alterations from developing, although some early changes do occur. After the drug is withdrawn following 28 days of therapy, treated animals still demonstrate no evidence of epileptiform discharges or changes in Na,K ATPase activity, although these changes persist in untreated cats. Given properly, phenytoin may prevent alterations in brain, which can result in the formation of a hyperexcitable population of cells. These data support the efficacy of early pharmacologic prophylaxis in posttraumatic epilepsy.
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PMID:Prophylactically administered phenytoin. Effects on the development of chronic cobalt-induced epilepsy in the cat. 12 75

The Ca2+-sensitive ATPase (adenosine triphosphatase) of human erythrocyte membranes is activated, not only by Ca2+ ions, but also by a series of other bivalent metal ions including Sr2+, Ba2+, Mn2+, Ni2+, Co2+, Cd2+, Cu2+, Zn2+ and Pb2+. The degree of activation is dependent on the radius of the ion rather than on its nature, in contrast with the dissociation constant of the enzyme--metal ion complex.
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PMID:Activation of membrane-bound high-affinity calcium ion-sensitive adenosine triphosphatase of human erythrocytes by bivalent metal ions. 12 84

ATPase (ATP phosphohydrolase, EC 3.6.1.3) was detected in the membrane fraction of the strict anaerobic bacterium, Clostridium pasteurianum. About 70% of the total activity was found in the particulate fraction. The enzyme was Mg2+ dependent; Co2+ and Mn2+ but not Ca2+ could replace Mg2+ to some extent; the activation by Mg2+ was slightly antagonized by Ca2+. Even in the presence of Mg2+, Na+ or K+ had no stimulatory effect. The ATPase reaction was effectively inhibited by one of its products, ADP, and only slightly by the other product, inorganic phosphate. Of the nucleoside triphosphates tested ATP was hydrolyzed with highest affinity ([S]0.5 v = 1.3 mM) and maximal activity (120 U/g). The ATPase activity could be nearly completely solubilized by treatment of the membranes with 2 M LiCl in the absence of Mg2+. Solubilization, however, led to instability of the enzyme. The clostridial solubilized and membrane-bound ATPase showed different properties similar to the "allotopic" properties of mitochondrial and other bacterial ATPases. The membrane-bound ATPase in contrast to the soluble ATPase was sensitive to the ATPase inhibitor dicyclohexylcarbodiimide (DCCD). DCCD, at 10(-4) M, led to 80% inhibition of the membrane-bound enzyme; oligomycin ouabain, or NaN3 had no effect. The membrane-bound ATPase could not be stimulated by trypsin pretreatment. Since none of the mono- or divalent cations had any truly stimulatory effect, and since a pH gradient (interior alkaline), which was sensitive to the ATPase inhibitor DCCD, was maintained during growth of C. pasteurianum, it was concluded that the function of the clostridial ATPase was the same as that of the rather similar mitochondrial enzyme, namely H+ translocation. A H+-translocating, ATP-consuming ATPase appears to be intrinsic equipment of all prolaryotic cells and as such to be phylogenetically very old; in the course of evolution the enzyme might have been developed to a H+-(re)translocating, ATP-forming ATPase as probably realized in aerobic bacteria, mitochondria and chloroplasts.
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PMID:Properties and function of clostridial membrane ATPase. 13 64

The properties of a Ca2+ activated adenosine triphosphatase shown to be present in homogenates of purified rat peritoneal mast cells were investigated. The enzyme was activated by Ca2+, Mg2+, and to a lesser extent by Mn2+ and Co2+. Ca2+ alone was necessary for full activity and the further addition of Mg2+ did not have any effect. The chelating agents EGTA (ethanedioxybis(ethylamine)tetra-acetate) and EDTA completely inhibited the reaction. The pH optimum was 7.8. Reduced glutathione, cysteine, dithiothreitol, N-ethylmaleimide, urea, ADP, NaF, increasing ionic strength and Triton X-100 all inhibited the reaction. On subcellular fractionation of mast-cell homogenates by density-gradient centrifugation, the distribution of Ca2+ activated adenosine triphosphatase resembled that of 5'-nucleotidase, but differed from that of the other markers used, suggesting localization in the plasma membrane. Further experiments indicated that the enzyme is present on the external surface of the plasma membrane.
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PMID:Characterization of calcium-ion-activated adenosine triphosphatase in the plasma membrane of rat mast cells. 13 82


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