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)

Selectively permeable membrane vesicles isolated from Simian virus 40-transformed mouse fibroblasts catalyzed Na+ gradient-coupled active transport of several neutral amino acids dissociated from intracellular metabolism. Na+-stimulated alanine transport activity accompanied plasma membrane material during centrifugation in discontinuous dextran 110 gradients. Carrier-mediated transport into the vesicle was demonstrated. When Na+ was equilibrated across the membrane, countertransport stimulation of L-[3H]alanine uptake occurred in the presence of accumulated unlabeled L-alanine, 2-aminoisobutyric acid, or L-methionine. Competitive interactions among neutral amino acids, pH profiles, and apparent Km values for Na+ gradient-stimulated transport into vesicles were similar to those previously described for amino acid uptake in Ehrlich ascites cells, which suggests that the transport activity assayed in vesicles is a component of the corresponding cellular uptake process. Both the initial rate and quasi-steady state of uptake were stimulated as a function of a Na+ gradient (external Na+ greater than internal Na+) applied artificially across the membrane and were independent of endogenous (Na+ + K+)-ATPase activity. Stimulation by Na+ was decreased when the Na+ gradient was dissipated by monensin, gramicidin D or Na+ preincubation. Na+ decreased the apparent Km for alanine, 2-aminoisobutyric acid, and glutamine transport. Na+ gradient-stimulated amino acid transport was electrogenic, stimulated by conditions expected to generate an interior-negative membrane potential, such as the presence of the permeant anions NO3- and SCN-. Na+-stimulated L-alanine transport was also stimulated by an electrogenic potassium diffusion potential (K+ internal greater than K+ external) catalyzed by valinomycin; this stimulation was blocked by nigericin. These observations provide support for a mechanism of active neutral amino acid transport via the "A system" of the plasma membrane in which both a Na+ gradient and membrane potential contribute to the total driving force.
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PMID:Active amino acid transport in plasma membrane vesicles from Simian virus 40-transformed mouse fibroblasts. Characteristics of electrochemical Na+ gradient-stimulated uptake. 6 32

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

The activity Na+, K+-ATPase of the guinea pig brain synaptosome fraction as well as the effect on this enzyme of the blood serum obtained in guinea pigs in different periods after sensibilization of the animals with the basic encephalitogenic protein were studied in dynamics of experimental allergic encephalomyelitis development. The Na+,K+-ATPase activity in the guinea pig brain synaptosome fraction is more than 50% lower from the seventh day of sensibilization up to development of characteristic symptoms of the disease in animals. The guinea pigs blood serum obtained on the seventh and tenth days of sensibilization has an inhibitory effect of the same order on the studied activity of the normal guinea pig brain synaptosome fraction. At the later stages of the disease development and with the presence of characteristic symptoms of experimental allergic encephalomyelitis in the animals the blood serum has no similar effect.
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PMID:[Na+-K+-ATPase activity in guinea pig brain synaptosomal fraction in experimental allergic encephalomyelitis]. 7 43

Ethacrynic acid, a known inhibitor of both Na+--K+ and Mg2+-activated ATPases, effectively inhibits histamine release from antigen-challenged human basophils in vitro. Ouabain, an inhibitor specific for Na+--K+-activated ATPases, shows no effect upon the quantity of histamine released from the antigen-challenged basophils. Ethacrynic acid also effectively inhibits Ca2+--ionophore A23187-induced release, implying it inhibits the Ca2+-dependent secretory stage of the histamine-release process. Inhibition of ATPases and histamine release by ethacrynic acid both require the presence of the olefinic bond in the ethacrynic-acid molecule. Possible utilization of analogues of ethacrynic acid as anti-allergic drugs and as a device to investigate the ATPase system of histamine-releasing cells is suggested.
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PMID:Blocking of histamine release from human basophils in vitro by the ATPase inhibitor, ethacrynic acid. 7 37

Sodium glycocholate was shown to remove a Ca2+-activated adenosine triphosphatase from the external surface of the rat mast cell without causing lysis. Sensitized mast cells pretreated with sodium glycocholate showed a decrease in histamine-releasing capacity when triggered with antigen, Synacthen and ATP. Release induced by calcium ionophore A23187 was unaffected.
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PMID:Effect of removal of calcium-activated adenosine triphosphatase from rat mast cells by treatment with sodium glycocholate. 7 27

Erythrocyte ghost (Na+ + K+) ATPase activity was studied in mice with hereditary muscular dystrophy (strain C 57 BL 6J/dy) and appropriate controls. No difference was observed in the enzymatic activity between dystrophic and any of the healthy genotypes. Ouabain 5 mM and 0.1 mM inhibited the enzymatic activity and no difference was observed between dystrophic and control animals. The results are discussed in the light of the literature.
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PMID:Erythrocyte ghost (Na+ + K+) ATPase activity in mice with hereditary muscular dystrophy (strain C57 BL/64J/dy). 7 52

Active ion exchanges across erythrocyte membrane from patients with Duchenne muscular dystrophy were studied by two methods: --erythrocyte ghosts (Na+,K+)ATPase activity and its sensibility to ouabain, using an enzymatic method; --active sodium outflux and its sensibility to ouabain using a radioisotopic method. (Na+,K+)ATPase activity and active sodium outflux were decreased in dystrophic patients compared to normal sex- and age-matched controls. Enzymatic activity and active sodium outflux were inhibited by ouabain 10(-4) M in patients and in controls. Inhibition of the active sodium outflux was lower in patients than in controls. The results are discussed in light of the literature.
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PMID:The sodium pump of erythrocytes from patients with Duchenne muscular dystrophy: effect of ouabain on the active sodium flux and on (Na+, K+)ATPase. 7 65

1. The inactive ATPases of four different mutant strains of Escherichia coli have been purified to homogeneity. 2. Molecular weights, subunit patterns in sodium dodecylsulfate electrophoresis and immunological properties of mutant and wild-type proteins are identical. The mutant enzymes compete with the wild-type enzyme for the binding sites on the membrane. 3. On freezing and thawing in salt solutions, the ATPase is split into subunits IA (alpha, gamma, epsilon), IB (delta; alpha, gamma, epsilon), and II (beta). By complementation in vitro of the isolated subunits, it is shown that subcomplex IA (alpha, gamma, epsilon) is altered in the mutant strains described here.
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PMID:Complementation in vitro of mutant and wild-type ATPase of Escherichia coli using isolated subunits. 7 46

As different structural states of the Na+-K+-ATPase (EC 3.6.1.3) may lead to a changed reactivity to antibodies, the influence of different ligands on the reaction between highly purified membrane-bound Na+-K+-ATPase and specific antibodies was investigated. The antigen antibody reaction was registered by measuring the antibody inhibition of Na+-K+-ATPase activity. It was found that Na+ decreased and K+ increased the antibody inhibition of the Na+-K+-ATPase activity of the membrane-bound enzyme if both Mg++ and ATP were present during the antigen antibody reaction. These effects were not observed if ATP was replaced by ADP or by the ATP analog adenylyl (beta-gamma-methylene) diphosphonate. If a solubilized enzyme preparation with the same specific activity was used the effects of Na+ or K+ which were demonstrated in the membrane-bound enzyme could not be detected. The study suggests that the Na+-K+-ATPase structure is altered by Na+ and K+, provided Mg++ and specifically the nucleotide ATP are also present. These structural changes are likely to occur during Na+-K+-transport and do not seem to be necessarily linked to the Na+, K+ and Mg++ stimulated ATP splitting of the enzyme.
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PMID:Immunological characterization of Na+ and K+ mediated structural states of rat kidney Na+-k+-ATPase. 8 Mar 2

Application of immunochemical methods for elucidating the Na+, K+-ATPase molecular organization and mechanism of action is discussed. The data of some authors who have studied the purified preparations of Na+, K+-ATPase from different sources show that both the catalytic subunit of the enzymic complex and its sialoglycoproteid have antigenic determinants. Antibodies, binding with these determinants, may either change or produce no effect on the enzymic process, link with the active transport of Na+ and K+. Antibodies used as conformation-sensitive explorers may yield the interesting information on organization of the Na+, K+-ATPase complex in the membrane and its conformation in different functional states which simultaneously with the data of the kinetic analysis and reconstruction of this enzymic complex would contribute to deciphering the mechanism of the Na+ and K+ active transport through biomembranes.
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PMID:[Immunochemical approach to explaining the molecular organization and mechanism of action of Na+,K+-ATPase]. 8 56


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