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)

Samples were obtained from the frontal and occipital cortex of Macaque monkeys at 4, 10 and 20 years of age. Electron microscopic studies revealed attenuation of capillary walls and declining numbers of endothelial mitochondria per capillary profile with increasing age. The basal lamina surrounding the capillary increased in thickness between 4 and 10 years of age; however, it did not undergo further change between 10 and 20 years. These results corroborate morphological and biochemical studies indicative of declining numbers of mitochondria, and decreasing mitochondrial ATP synthesis and ATPase activity in other tissues during aging.
J Gerontol 1979 Sep
PMID:Thinning of capillary walls and declining numbers of endothelial mitochondria in the cerebral cortex of the aging primate, Macaca nemestrina. 11 44

1. The effects of ouabain on renin secretion by rat renal cortical slices were studied. 2. Renin secretion was inhibited by 10(-3) M-ouabain in the presence of free Ca (10(-4) to 2.6 x 10(-3) M). Inhibition was blocked at Ca less than 10(-8) M. 3. The effect of free Ca on ouabain-inhibition was shown to be independent of the presence of EGTA, completely reversible, and unrelated to passive leakage of renin from non-viable cells, as assessed by simultaneous release of lactate dehydrogenase activity (LDH). 4. It is proposed that, as a result of inhibition of Na, K-ATPase by ouabain, (a) intracellular Na increases in the renin-secreting juxtaglomerular cells, (b) intracellular Ca increases, via an Na-Ca exchange mechanism, and (c) that Ca accumulation, in some unknown manner, inhibits renin secretion.
J Physiol 1979 Sep
PMID:Possible mechanism of the inhibitory effect of ouabain on renin secretion from rat renal cortical slices. 11 99

The source of metabolic energy for the accumulation of methionine in cells of Escherichia coli was shown to differ from that for proline uptake. In contrast to proline uptake, methionine accumulation was sensitive to arsenate, and relatively resistant to azide or dinitrophenol. Adenosine triphosphatase mutant strains also differentiated between the two systems, consistent with the conclusion that, although proline uptake is driven directly by the energized membrane state, methionine uptake is not. Methionine transport is similar to that of other osmotic shock-sensitive systems in its direct utilization of adenosine 5'-triphosphate or a related compound as energy source.
J Bacteriol 1975 Sep
PMID:Energy coupling for methionine transport in Escherichia coli. 12 47

Beef heart mitochondrial ATPase (F1) contained 2 mol of ADP and 1 mol of ATP/mol of enzyme, which resisted removal by Sephadex chromatography with dilute buffers or repeated precipitation with ammonium sulfate. The native enzyme also contained two apparently equivalent binding sites, which participated in readily reversible binding of adenyl-5'-ylimidodiphosphate (AMP-P(NH)P), with a Kd of 1.3 mum. The failure of AMP-P(NH)P to compete effectively with ADP for binding sites on F1 may be related to the failure of the analog to inhibit oxidative phosphorylation. Virtually complete removal of all adenine nucleotides from F1 occurred when the enzyme was chromatographed on columns of Sephadex equilibrated with 50% glycerol. No loss in ATPase activity was observed following removal of nucleotides from the enzyme, which was then capable of binding more than 4 mol of ADP and almost 5 mol of AMP-P(NH)P/mol of protein. Subsequent chromatography on columns of Sephadex equilibrated with dilute buffers containing Mg2+ removed only 1.5 mol of ADP and no AMP-P(NH)P from the enzyme. Reconstitution of F1 with ADP or with almost 5 mol of AMP-P(NH)P resulted in preparations that exhibited an undiminished capacity to restore oxidative phosphorylation in F1-deficient submitochondrial particles.
J Biol Chem 1975 Sep 10
PMID:Interaction of adenine nucleotides with multiple binding sites on beef heart mitochondrial adenosine triphosphatase. 12 56

A pronounced effect of concanavalin A (Con A) upon activity of ecto-5'-nucleotidase of intact C6 glioma cells in culture has been demonstrated. A near linear rate of decrease in 5'-nucleotidase activity was observed upon treatment with concentrations of Con A up to 0.25 muM. Nonspecific phosphatase activity and Ca2+-dependent ATPase activity were not inhibited by Con A treatment of the cells. Of the total 5'-nucleotidase activity of C6 cells (Vmax = 5.0 mumol of Pi liberated/mg of cell protein/hour), approximately 20% still remained after treatment with high concentrations of Con A. The inhibitory effect of Con A operated to reduce substantially Vmax for ecto-5'-nucleotidase. Inhibition was reversed by briefly incubating the Con A-treated cells with alpha-methyl-D-glucoside, or alpha-methyl-D-mannoside, the later being more effective. These findings suggest that a relatively specific, reversible, inhibition of ecto-5'-nucleotidase results from Con A binding to the surface of the intact cultured mammalian cells.
J Biol Chem 1975 Sep 10
PMID:Concanavalin A inhibition of ecto-5'-nucleotidase of intact cultured C6 glioma cells. 12 59

A cytochemical method for the light and electron microscope localization of the K- and Mg-dependent phosphatase component of the Na-K-ATPase complex was applied to rat kidney cortex, utilizing p-nitrophenylphosphate (NPP) as substrate. Localization of K-N-ATPase activity in kidneys fixed by perfusion with 1% paraformaldehyde -0.25% glutaraldehyde demonstrated that distal tubules are the major cortical site for this sodium transport enzyme. Cortical collecting tubules were moderately reactive, whereas activity in proximal tubules was resolved only after short fixation times and long incubations. In all cases, K-NPPase activity was restricted to the cytoplasmic side of the basolateral plasma membranes, which are characterized in these neplron segments by elaborate folding of the cell surface. Although the rat K-NPPase appeared almost completely insensitive to ouabain with this cytochemical medium, parallel studies with the more glycoside-sensitive rabbit kidney indicated that K-NPPase activity in these nephron segments is sensitive to this inhibitor. In addition to K-NPPase, nonspecific alkaline phosphatase also hydrolyzed NPP. The latter could be differentiated cytochemically from the specific phosphatase, since alkaline phosphatase was K-independent, insensitive to ouabain, and specifically inhibited by cysteine. Unlike K-NPPPase, alkaline phosphatase was localized primarily to the extracellular side of the microvillar border of proximal tubules. A small amount of cysteine-sensitive activity was resolved along peritubular surfaces of proximal tubules. Distal tubules were unreactive. In comparative studies, Mg-ATPase activity was localized along the extracellular side of the luminal and basolateral surfaces of proximal and distal tubules and the basolateral membranes of collecting tubules.
J Cell Biol 1975 Sep
PMID:Transport ATPase cytochemistry: ultrastructural localization of potassium-dependent and potassium-independent phosphatase activities in rat kidney cortex. 12 60

Sodium-potassium-activated adenosine triphosphatase (Na-K-ATPase) is associated with electrolyte transport in many tissues. To help delineate its role in intestinal transport, changes in rat intestinal electrolyte and water transport induced by injecting methylprednisolone acetate 3 mg/100 g or deoxycorticosterone acetate (DOCA) 0.5 mg/100 g per day for 3 days were correlated with changes in Na-K-ATPase activity. Methylprednisolone increased sodium and water absorption, potassium secretion, transmural potential difference, and Na-K-ATPase activity in the jejunum, ileum, and colon. Examination of isolated epithelial cells demonstrated that the jejunal and ileal increase in Na-K-ATPase occurred in both the villus tip and crypermeability, Mg-ATPase, and adenylate cyclase activities were unchanged by methylprednisolone. DOCA increased sodium and water absorption, potassium secretion, transmural potential difference, and Na-K-ATPase activity in the colon alone. Colonic Mg-ATPase and adenylate cyclase activities were unaffected. Jejunal and ileal enzyme activity, electrolyte transport, and permeability were unchanged by DOCA. Methylprednisolone and DOCA were not additive in their effect on colonic Na-K-ATPase activity. Methylprednisolone and DOCA increased electrolyte and water transport and Na-K-ATPase activity concomitantly in specific segments of small intestine and colon. These data are consistent with an important role for Na-K-ATPase in intestinal electrolyte and water transport.
J Clin Invest 1975 Sep
PMID:Na+-K+-activated adenosine triphosphatase and intestinal electrolyte transport. Effect of adrenal steroids. 12 64

Hybrid membrane particles from two mutants of Escherichia coli K12, Bv4 and K11, defective in oxidative phosphorylation, have been prepared, in which ATP-driven membrane energization is restored. A soluble factor of mutant K11 was found to have properties similar to parental crude coupling factor, ATPase (EC 3.6.1.3). Membrane particles of this mutant could not be reconstituted by parental coupling factor. Either parental coupling factor, or the soluble factor of mutant K11 could reconstitute both respiration-driven and ATP-driven energization to membrane particles of mutant Bv14 or to parental particles depleted of ATPase. Mutant Bv4 was found to be devoid of coupoing factor activity, while retaining the ability to hydrolyze ATP. Both mutants possess an ATPase with an altered binding to the membrane. Mutant K11 is impaired in respiration-driven amino acid transport, in contrast to mutant Bv4. The three major subunits of parental Escherichia coli ATPase have been isolated and antibodies have been prepared against these subunits. Antibodies against the largest subunit (alpha component) or against the intact catalytic subunits (alpha + beta components) inhibit both ATP-Pi exchange in the parent organism as well as ATP hydrolytic activity in parent and mutants. Antibodies against the two other subunits (beta or gamma components) also inhibit these two reactions, but were found to be less effective. Mutant N144, which lacks ATPase activity, shows no precipitin lines with anti-alpha, anti-beta, anti-gamma, or anti (alpha + beta) preparations. In contrast, mutants Bv4 and K11, exhibit cross-reactivity with all of the antisera.
Biochim Biophys Acta 1975 Sep 08
PMID:Differentiation between mutants of Escherichia coli K defective in oxidative phosphorylation. 12 79

1. Purification of the coupling factor ATPase from Rhodospirillum rubrum has been achieved by a combination of a previously described procedure with chromatography on DEAE-Sephadex A50. 2. Identification of the coupling factor ATPase during purification, and estimation of the relative amount of the enzyme in each fraction was greatly simplified by utilization of its unusual fluorescence. 3. Preparations of R. rubrum coupling factor ATPase injected into rabbits yielded antisera which were suitable for following the course of purification. 4. Judged by immunoelectrophoretic analysis and polyacrylamide gel electrophoresis the final preparation was pure. Under standardized conditions, apparently pure preparations showed fluorescence ratios at 300/350 nm of 3-6, which are considerably higher than those reported for pure CF1 from chloroplasts. 5. The enzyme lost its activity and changed its immunological identity during prolonged storage and by treatment with urea. Antisera against urea-treated enzyme showed the presence of two distinct antigens in the modified preparations.
Biochim Biophys Acta 1975 Sep 08
PMID:Immunological and fluorescence studies with the coupling factor ATPase from Rhodospirillum rubrum. 12 80

The influence of the mode of preparation upon some of the characteristics of white adipose tissue plasma membranes and microsomes has been reported. Plasma membrane fractions prepared from mitochondrial pellet were shown to have higher specific activities of (Mg2+ + Na+ + K+)-ATPase than plasma membranes originating in crude microsomes. Isolation of fat cells by collagenase treatment was found to result in a decrease in specific activity of the plasma membrane enzymes; in plasma membranes prepared from isolated fat cells, the specific activity values obtained for (Mg2+ + Na+ +k+)-ATPase and 5'-nucleotidase were only 42% and 6.3% respectively of those obtained in plasma membranes prepared from whole adipose tissue. Purification of whole adipose tissue crude microsomes by hypotonic treatment caused extensive solubilization of the endoplasmic reticulum marker enzymes, NADH oxidase and NADPH cytochrome c reductase. The lability of endoplasmic reticulum marker enzymes, however, was found to be greatly diminished in the preparations from isolated fat cells. The possibility that NADH oxidase and NADPH cytochrome c reductase activities found in the plasma membranes are microsomal enzymes adsorbed by the plasma membranes is discussed. The peptide patterns as well as the NADH oxidase and NADPH cytochrome c reductase activity patterns of plasma membranes and purified microsomes were compared by means of sodium dodecyl sulfate or Triton X-100 polyacrylamide gel electrophoresis.
Biochim Biophys Acta 1975 Sep 16
PMID:Comparison of plasma membranes and endoplasmic reticulum fractions obtained from whole white adipose tissue and isolated adipocytes. 12 89


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