Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P20020 (adenosine triphosphatase)
 3,299 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Treatment with neuraminidase decreased the activity of Na+,K+-activated Mg2+-adenosine triphosphatase in plasma membranes isolated from experimental granulation tissue but not that of 5'-nucleotidase or leucine-beta-naphthylamidase. A temporary lowering of the pH of the plasma membrane suspension to 2-3 inactivated all three enzymes, which remained inactive after the pH had been readjusted to 7.4. Addition of dextran preparations to the membrane suspension decreased the activity of adenosine triphosphatase. Ethanol (0.4%) had a similar effect. These marker enzymes of plasma membranes were not affected by additions of hyaluronate, chondroitin sulfate, protein polysaccharide or soluble collagen. Serotonin stimulated the adenosine triphosphatase activity slightly. About 10-20% of the protein in the plasma membrane preparation was extracted with EDTA. This "fuzzy coat" fraction yielded a distinct gel-electrophoretic protein pattern. Hyaluronidase was not helpful in cleaving this surface layer from the plasma membranes.
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PMID:Properties of plasma membranes from granulation tissue with reference to extracellular matrix. 0 56

1. A procedure was developed for the preparation of plasma membranes from experimental granulation tissue of the rat without the addition of enzymes. The yield is better than 20% and the purification at least tenfold. 2. Values are given for the activities of 5'-nucleotidase, Na-+, k-+-activated Mg-2+dependent adenosine triphosphatase and leucine beta-naphthylamidase, for lipid composition, and for the gel-electrophoretic patterns of proteins and glycoporteins in the membrane preparations. 3. The plasma membranes from the mature granulation tissue contain proportionally more protein in the lipid phase, but the specific activities of 5'-nucleotidase and Na-+,K-+-activated Mg-2+-dependent adenosine triphosphatase are smaller than in the proliferating tissue. Certain differences were repeatedly observed in the gel-electrophoretic patterns of the developmental phases. 4. The plasma membranes from the granulation tissue were compared with those from rat peritoneal macrophages and from embryonic-chick tendon cells.
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PMID:Plasma membranes from experimental granulation tissue. 12 81

1. Six rat liver plasma-membrane subfractions of different density and morphological, enzymic and chemical properties were prepared from homogenates by a combination of differential, rate-zonal and density-gradient centrifugation. They consisted of three vesicular 'light' subfractions of density 1.12-1.13 and three 'heavy' subfractions of density 1.16-1.18 containing membrane strips and intercellular junctions. 2. All six subfractions contained a basal adenylate cyclase activity. One of the 'light' subfractions that showed the highest glucagon-stimulated adenylate cyclase activity was identified as deriving form the blood-sinusoidal face of the hepatocyte. This subfraction, unlike the others, was contaminated by Golgi components, as indicated by its morphological properties and the presence of galactosyl- and sialyl-transferase activities. 3. All the six subfractions showed high activities of the following plasma-membrane marker enzymes: 5'-nucleotidase, alkaline phosphodiesterase (nucleotide pyrophosphatase), alkaline phosphatase, leucine naphthylamidase and Mg2+-activated adenosine triphosphatase. A 'light' subfraction that showed the highest specific activities of all the above marker enzymes, but lacked a glucagon-stimulated adenylate cyclase activity, was identified as deriving from the bile-canalicular face of the hepatocyte. 4. The 'heavy' subfractions, which showed generally the lowest activities of the above plasma-membrane enzyme markers, and were characterized by the presence of desmosomes and gap junctions, were taken to originate from the contiguous faces of the hepatocyte. 5. The protein composition of the six subfractions was generally similar, as shown by polyacrylamide-gel electrophoresis. Differences in the amounts of various protein and glycoprotein bands among the subfractions correlated with their morphology, enzymic composition and sialic acid content. 6. Hormonal and histochemical evidence supporting the identification of a bile-canalicular subfraction, a blood-sinusoidal subfraction and contiguous-face subfractions is discussed.
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PMID:Functional polarity of the rat hepatocyte surface membrane. Isolation and characterization of plasma-membrane subfractions from the blood-sinusoidal, bile-Canalicular and contiguous surfaces of the hepatocyte. 12 84

Growth of Halobacterium halobium under illumination with limiting aeration induces bacteriorhodopsin formation and renders the cells capable of photophosphorylation. Cells depleted of endogenous reserves by a starvation treatment were used to investigate the means by which energy is coupled to the active transport of [14C]proline, -leucine, and -histidine. Proline was readily accumulated by irradiated cells under anaerobiosis even when the photophosphorylation was abolished by the adenosine triphosphatase inhibitor N,N'-dicyclohexylcarbodimiide (DCCD). The uptake of proline in the dark was limited except when the cells were allowed to accumulate adenosine 5'-triphosphate (ATP) by prior light exposure or by the oxidation of glycerol. DCCD inhibited this dark uptake. These findings essentially support Mitchell's chemiosmotic theory of active transport. The driving force is apparently the proton-motive force developed when protons are extruded from irradiated bacteriorhodopsin or by the dydrolysis of ATP by membrane adenosine triphosphatase. Carbonylcyanide m-chlorophenylhydrazone (CCCP), a proton permeant known to abolish membrane potential, was a strong inhibitor of proline uptake. Leucine transport was also apparently driven by proton-motive force, although its kinetic properties differed from the proline system. Histidine transport is apparently not a chemiosmotic system. Dark- or light-exposed cells show comparable initial rats of histidine uptake, and these processes were only partially inhibited by DCCD or CCCP. The histidine system apparently does not utilize ATP per se since comparable rates of uptake were exhibited by cells of differing intracellular ATP levels. Irradiated cells did effect a greater total accumulation of histidine than dark-exposed cells. These findings suggest that ATP is needed for sustained transport.
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PMID:Energy coupling in the active transport of amino acids by bacteriohodopsin-containing cells of Halobacterium holobium. 12 52

Temporal patterns of biosynthesis of the Ca2+ + Mg2+-dependent adenosine triphosphatase of sarcomplasmic reticulum were obtained from studies with primary cultures of rat skeletal muscle cells. Rates of synthesis at various stages of differentiation were estimated from the incorporation of tritium-labeled leucine into the ATPase. Cells were solubilized with detergent, and newly synthesized ATPase was isolated from cells by antibody precipitation in the presence of carrier ATPase. Radioactivity incorporated into the ATPase was determined after gel electrophoresis of the precipitates and counting of gel slices containing the ATPase band. In Dulbecco's modified Eagle's medium containing 10% horse serum and 0.5% chick embryo extract, mononucleated myoblast cells began to form multinucleated myotubes after about 50 hours in culture. Prior to fusion little ATPase synthesis was detectable; during fusion the ATPase was synthesized at an accelerating rate for a period of about 30 hours. The rate of synthesis levelled off after about 90 hours coincident with termination of fusion. In Dulbecco's modified Eagle's medium containing 20% fetal calf serum and 8% embryo extract, the onset of fusion was delayed for 30 to 40 hours. In this medium biosynthesis of the ATPase was also delayed so that biosynthesis of the ATPase appeared to be correlated with fusion of muscle cells. Cells cultured in Culbecco's modified Eagle's medium containgin 10% horse serum, but only 60 muM Ca2+, proliferated but did not fuse. Under these conditions, synthesis of the ATPase was measurable at 50 to 60 hours, and the rate of synthesis accelerated until 120 hours when it declined. Under all conditions degradation of the ATPase occurred with a half-life of 20 hours whereas the half-life of total protein degradation was 40 hours. Synthesis of the sarcoplasmic reticulum ATPase, like that of a number of other muscle-specific proteins, is greatly accelerated as myoblasts fuse and differentiate into myotubes. Fusion is not essential for this phenomenon, however, although it is normally concomitant with it.
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PMID:Assembly of the sarcoplasmic reticulum. Biosynthesis of the adenosine triphosphatase in rat skeletal muscle cell culture. 13 98

The activities of 5'-nucleotidase, K+, Na+-activated Mg2+-dependent adenosine triphosphatase (ATPase) and leucine-beta-naphthylamidase were determined from 17 rheumatoid synovial fluids and from extracts of the corresponding synovial tissues. There was little correlation between the enzyme activities in the synovial fluids and those in the respective synovial-tissue extracts. In seropositive cases of rheumatoid arthritis the activities of 5'-nucleotidase and leucine-beta-naphthylamidase in the synovial-tissue extract were higher than in seronegative cases. Also, the ratios of the enzyme activities in the synovial fluids to the resepctive activities in synovial tissue were lower in the seropositive cases. The activity of 5'-nucleotidase in the synovial tissue decreased during gold treatment.
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PMID:The activities of plasma-membrane marker enzymes in rheumatoid synovial tissues and fluids. 13 78

Synthesis of total cellular proteins of Escherichia coli was studied upon transfer of a log-phase culture from 30 (or 37) to 42 degrees C. Cells were pulse-labeled with [3H]leucine, and the labeled proteins were analyzed by gel electrophoresis in the presence of sodium dodecyl sulfate. The rates of synthesis of at least five protein chains were found to increase markedly (5- to 10-fold) within 5 min after temperature shift-up and gradually decrease to the new steady-state levels, in contrast to the majority of proteins which gradually increase to the steady-state levels (about 1.5-fold the rate at 30 degrees C). Temperature shift-down did not cause any appreciable changes in the pattern of protein synthesis as detected by the present method. Among the proteins greatly affected by the temperature shift-up were those with apparent molecular weights fo 87,000 (87K), 76K, 73K, 64K, and 61K. Two of them (64K and 61K) were found to be precipitated with specific antiserum against proteins that had previously been shown to have an adenosine triphosphatase activity. The bearings of these findings on bacterial adaptation to variation in growth temperature are discussed.
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PMID:Transient regulation of protein synthesis in Escherichia coli upon shift-up of growth temperature. 14 9

The biosynthesis of the Ca2+- and Mg2+-dependent adenosine triphosphatase of sarcoplasmic reticulum was studied in cell cultures of embryonic chick heart. Rates of synthesis were estimated from the incorporation of tritium-labeled leucine into the ATPase. Newly synthesized ATPase was isolated from cells by immunoprecipitation. Radioactive leucine incorporation into the ATPase was determined by gel electrophoresis of the immunoprecipitates and counting of gel slices containing the ATPase band. Accumulation of the ATPase was estimated from the concentration of Ca2+ and Mg2+-dependent, hydroxylamine-sensitive phosphoprotein in the whole cell membrane fraction of cultured cells. Embryonic heart cells cultured in a medium which permitted cell proliferation showed approximately linearly increasing rates of ATPase synthesis and accumulation/culture plate as the cells proliferated. When cells were cultured in a serum-free medium, cell proliferation was inhibited and there was no sustained increase in the rate of ATPase synthesis or accumulation. Inclusion of isoproterenol or dibutyryl cyclic AMP at concentrations of 10 microM up to 1 mM in serum-free culture medium failed to stimulate significantly ATPase synthesis.
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PMID:Biosynthesis of the Ca2+- and Mg2+-dependent adenosine triphosphatase of sarcoplasmic reticulum in cell cultures of embryonic chick heart. 22 35

Amino acid transport rates and amino acid binding proteins were examined in a strain containing the rho-120 mutation (formerly SuA), which has been shown to lower the rho-dependent, ribonucleic acid-activated adenosine triphosphatase activity to 9% of the rho activity in the isogenic wild-type strain. Tryptophan and proline transport, which occur by membrane-bound systems, were not altered. On the other hand, arginine, histidine, leucine, isoleucine, and valine transport were variably increased by a factor of 1.4 to 5.0. Kinetics of leucine transport showed that the LIV (leucine, isoleucine, and valine)-I (binding protein-associated) transport system is increased 8.5-fold, whereas the LIV-II (membrane-bound) system is increased 1.5-fold in the rho mutant under leucine-limited growth conditions. The leucine binding protein is increased fourfold under the same growth conditions. The difference in leucine transport in these strains was greatest during leucine-limited growth; growth on complex media repressed both strains to the same transport activity. We propose that rho-dependent transcriptional termination is important for leucine-specific repression of branched-chain amino acid transport, although rho-independent regulation, presumably by a corepressor-aporepressor-type mechanism, must also occur.
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PMID:Regulation of amino acid transport in Escherichia coli by transcription termination factor rho. 32 70

The ATP-energy transducing system in membranes of Escherichia coli is inhibited by dicyclohexylcarbodiimide. The protein component of this complex with which carbodiimides covalently react to inhibit function was previously identified by labeling wild type and dicyclohexylcarbodiimide-resistant mutants with dicyclohexyl[14C]carbodiimide (Fillingame, R. H. (1975) J. Bacteriol. 124, 870-883). This specific carbodiimide-reactive protein has now been purified. The protein was extracted from the membrane with chloroform:methanol and chromatographed on DEAE-cellulose and hydroxypropyl Spehadex G-50 in this sulvent mixture. The resultant 700-fold purification yielded a protein that was homogeneous on dodecyl sulfate-acrylamide gel electrophoresis and virtually free of phospholipid. It remained soluble in neutral chloroform:methanol throughout the purification procedure. The amino acid composition of the purified protein was extraordinary in that only 16% of the amino acids present could be considered polar. Histidine, serine, cysteine, and tryptophan were not found. Abnormally high contents of methionine, glycine, alanine, and leucine were present. One mole of lysine and threonine were found/mole of dicyclohexyl[14C]carbodiimide bound. The minimum molecular weight based on the amino acid composition was 8400. The specific carbodiimide-reactive protein has also been purified without prior modification by dicyclohexylcarbodiimide. The unmodified protein eluted from DEAE-cellulose at a higher salt concentration than the dicyclohexylcarbodiimide-modified form, which suggested that the reaction with the carbodiimide neutralized the negative charge. Only one-third of the total carbodiimide-reactive protein in the membrane was modified by dicyclohexylcarbodiimide under conditions which maximally inhibited adenosine triphosphatase activity. These results rais the possibility that the carbodiimide-reactive protein may be present as an oligomer in the energy-transducing complex. The purification of the unmodified carbodiimide-reactive protein should permit assessment of tis biological function, particularly its role in the protein-translocation process that is catalyzed by this energy-transducing complex.
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PMID:Purification of the carbodiimide-reactive protein component of the ATP energy-transducing system of Escherichia coli. 78 71


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