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 enzyme activities of Mg2+ stimulated ATPase, creatine phosphokinase (CPK), myokinase (MK) and lactate dehydrogenase (LDH) were determined in pooled fast twitch (FT) and slow twitch (ST) human skeletal muscle fibers, dissected out from freeze-dried muscle biopsy material. All enzymes investigated demonstrated higher activities in FT fibres. The ratio in enzyme activity between fibre types was greatest for Mg2+ stimulated ATPase (3:1) and smallest for CPK (1.3:1). In addition, the isozyme patterns of CPK, MK and LDH were studied by means of isoelectric focusing (CPK and MK) and discelectrophoresis (LDH). A difference was observed between fibre types with respect to the isozyme distribution of MK and LDH, whereas the CPK isozyme pattern was similar in both fibre types. These results on separated human FT and ST fibres were essentially in conformity with what has earlier been indicated from experiments on mixed muscle homogenates.
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PMID:Actomyosin ATPase, myokinase, CPK and LDH in human fast and slow twitch muscle fibres. 19 Aug 69

The effect of medium Ca2+ concentration upon the concentration and the rate of synthesis of muscle proteins was investigated in chicken pectoralis muscle cultures. There is an easily identifiable class of muscle protein which includes the Ca2+-ATPase of sarcoplasmic reticulum, myosin, troponin C, ATP : creatine phosphotransferase, muscle specific actin, tropomysin 1 and 2, and muscle hemagglutinin, which show a large increase in concentration during normal development. The increased synthesis of these proteins was inhibited, without inhibition of cell proliferation, in culture media of relatively low Ca2+ concentration, 0.05--0.3 mM, where fusion was prevented. Similar medium Ca2+ concentration was required for the expression of all these proteins, suggesting their coordinate regulation. The proteins are denoted as 'calcium-modulated proteins'. The increased Ca2+ transport activity of sarcoplasmic reticulum in cultured chicken pectoralis muscle cells during development at 1.8 mM medium calcium concentration represents de novo synthesis of the Ca2+ transport ATPase, as shown by immunoprecipitation, active site labeling and direct identification of the Ca2+ transport ATPase on two-dimensional gel electropherograms of whole muscle homogenates. The concentration and the turnover rate of the majority of the muscle proteins is not affected significantly by medium Ca2+ concentration between 0.06 and 1.8 mM. It is proposed that increase in cytoplasmic free Ca2+ concentration during fusion plays a central role in the regulation of the synthesis of calcium-modulated proteins.
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PMID:Synthesis of the calcium transport ATPase of sarcoplasmic reticulum and other muscle proteins during development of muscles cells in vivo and in vitro. 22 45

Enzymatic properties of erythrocyte membranes in Duchenne muscular dystrophy (DMD) and malignant hyperthermia (MH), two genetically determined abnormalities of skeletal muscle, were examined. Acetylcholinesterase (AChE) and ATPase activities were chosen for investigation since alterations in these enzymes have been demonstrated in animal models of dystrophy. A significant decrease in Na+,K+-ATPase activity was noted in DMD patients and a number of possible DMD carriers, suggesting that this enzyme may provide a useful marker of the carrier state in carriers not exhibiting an elevation in plasma creatine phosphokinase activity. No abnormalities in AChE were demonstrable in any of our DMD patients, indicating that human dystrophy is biochemically distinct from certain animal models of dystrophy (e.g., dystrophic mice) where erythrocyte AChE is decreased. In contrast, evidence was found in two known MH carriers, who had normal erythrocyte ATPase activities, for the presence of an altered membrane AChE characterized by an increase in substrate affinity and a large decrease in maximal hydrolytic rate. While the exact relevance of this membrane defect, if any, to the pathogenesis of MH remains to be seen, the presence of this modified enzyme may serve to identify those individuals in a family where a positive history of MH exists who are at risk of developing a hyperthermic crisis during anesthesia.
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PMID:Erythrocyte membrane enzyme abnormalities in two hereditary disorders of muscle. 23 Oct 77

A decrease in creatine phosphokinase (CPK) activity was observed in plasma membranes (PM) treated with native A/WSN influenza virus but not in PM treated with heat-inactivated virus. The decrease in CPK activity depended on the amount of virus added to PM, on the pH of the medium and on the quality of the isolated PM. It was evident already after 10 minutes of incubation at 37 degrees C. The possible mechanism of the inhibition of the CPK activity and the relation to changes in adenosine triphosphatase (ATPase) activity and to fusion are discussed.
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PMID:Interaction of plasma membranes with influenza virus. V. Changes in creatine phosphokinase activity. 23 70

1. Addition of a non-dialysable, heat-labile and acid-precipitable factor which was not absorbed on DEAE-cellulose column, could restore the sensitivity of the chromatographed muscle pyruvate kinase from Marphysa sanguinea towards phosphocreatine inhibition. 2. This factor, being non-specific as it acts on pyruvate kinase isozymes from different sources, demonstrated high creatine kinase activity. 3. High concentrations of ADP, creatine or replacement of ADP with IDP/UDP or high pH abolished the inhibition indicating that the inhibition was mediated through creatine kinase by depleting ADP. 4. Apparent inhibition of phosphocreatine was related to the relative activities of 3 intracellular enzymes--pyruvate kinase, creatine kinase and adenosine triphosphatase.
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PMID:Apparent inhibition of pyruvate kinase by phosphocreatine and phosphoarginine. 31 98

Mitochondrial and microsomal fractions were isolated from guinea pig myocardium by differential pelleting. The mitochondrial fraction was subjected to analytical subfractionation by sucrose density gradient centrifugation and the gradient fractions assayed for marker enzymes for the various mitochondrial compartments, viz outer membrane (monoamine oxidase), intermembranous space (adenylate kinase), inner membrane (Mg2+-dependent ATPase and cytochrome c oxidase) and mitochondrial matrix (malate dehydrogenase), and for creatine kinase. Both creatine kinase and adenylate kinase were released by suspending the mitochondria in 50 mmol . litre-1 sodium phosphate buffer. Sonication or disruption with the detergent, digitonin released the adenylate kinase but the creatine kinase remained associated with the inner membranes. Subsequent salt treatment desorbed the creatine kinase from these membranes. It is concluded that creatine kinase is located to the outer aspect of the inner mitochondrial membrane. Analytical subfractionation of the microsomal fraction clearly resolved markers for the sarcolemma (5'-nucleotidase), outer mitochondrial membrane (monoamine oxidase) and endoplasmic reticulum (neutral alpha-glucosidase and RNA). Creatine kinase was localised in the endoplasmic reticulum particularly the smooth membranes.
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PMID:Sub-mitochondrial and sub-microsomal distribution of creatine kinase in guinea pig myocardium. 51 58

The M-line protein which is identical to the muscle form of creatine kinase was purified from rabbit skeletal muscle using ion exchange chromatography. Gel electrophoresis in the presence and absence of sodium dodecyl sulfate revealed the protein to be homogeneous. Sodium dodecyl sulfate gel electrophoresis gave 44 000 +/- 2000 as the minimum molecular weight while low speed sedimentation equilibrium experiments yielded a molecular weight of 84 000 +/- 4000, suggesting that the parent molecule is a dimer. Circular dichroism spectra revealed the presence of two negative dichroic bands located at 218 and 208 nm suggesting the presence of some beta-structure. Ellipticity values at these two wavelengths were -8000 +/- 400 and -9000 +/- 400 deg-cm2-dmol-1. Circular dichroism measurements indicated the protein to interact with myosin, heavy meromyosin and heavy meromyosin subfragment 1 (S1). The Ca2+-activated ATPase activities of myosin, heavy meromyosin and subfragment 1 were inhibited by the addition of M-line protein. When the protein was mixed with subfragment 1 in a 1:1 mole ratio in 0.15 M KC1, 50 mM Tris pH 8, low speed sedimentation equilibrium studies gave a molecular weight of 205 000 +/- 10 000 for the complex, indicative of an interaction of the two components. Both circular dichroism and sedimentation equilibrium studies indicated no interaction of M-line protein with light meromyosin.
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PMID:Physicochemical studies on the creatine kinase M-line protein and its interaction with myosin and myosin fragments. 79 21

Metal (Me) and MeATP interactions with adenylate cyclases associated with rabbit ventricular particles and with a detergent-dispersed preparation from rat cerebellum have been studied. data were simulated to fit kinetic models in which an inhibitor (HATP or ATP) is added in constant proportion to the variable substrate (MeATP). The specific models considered were that the enzyme binds (a) MeATP as the substrate; (b) MeATP as the substrate and HATP or ATP as an inhibitor; (c) MeATP as the substrate and free Me as an activator; and (d) MeATP as the substrate, free Me as an activator, and HATP or ATP as an inhibitor. Both equilibrium-ordered and random (rapid equilibrium assumption) types of sequential kinetic models were considered. The various models were tested using cardiac particulate adenylate cyclase in the presence of either a phosphoenolpyruvate-pyruvate kinase or a creatine phosphate-creatine kinase ATP-regeneration system. Although the enzyme with either system appeared to bind Mg2+ as an activator, one or both ATP-regeneration systems also seemed to interact directly with adenylate cyclase, making clear interpretations difficult. With the phosphoenolpyruvate-pyruvate kinase system, kinetic patterns on double reciprocal plots were linear as a function of MgATP, but with creatine phosphate-creatine kinase, kinetic patterns were concave downward. The kinetic models were further tested using the detergent-dispersed cerebellar enzyme, a preparation with low adenosine triphosphatase activity and not requiring the addition of an ATP-regeneration system. Reciprocal plots were linear and intersecting as a function of either MeATP or Me (Me = Mg2+ or Mn2+), and secondary replots of slopes and intersecting as function of either MeATP or Me (Me = Mg2+ or Mn2+), and secondary replots of slopes and intercepts also were linear. These data indicate that the brain detergent-dispersed enzyme conforms to a bireactant, sequential mechanism where free cation is a required activator and free ATP is not a potent inhibitor.
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PMID:Metal and metal-ATP interactions with brain and cardiac adenylate cyclases. 119 61

The targeting of creatine kinase isoenzymes to specific sites within muscle cells provides a system for the regeneration of ATP in situ from ADP and creatine phosphate. We have recently reported the colocalization of brain-type (B) creatine kinase and the nonsarcomeric mitochondrial creatine kinase isoenzymes in the thick ascending limb of the loop of Henle in the rat kidney, suggesting that creatine kinase may regenerate ATP for sodium transport (Friedman, D.L., and Perryman, M.B. (1991) J. Biol. Chem. 266, 22404-22410). In order to test the hypothesis regarding the association of B creatine kinase with sodium transport, we examined the creatine kinase enzymes in the rectal (salt-secreting) gland of the dogfish shark which contains high levels of the Na+/K(+)-ATPase. The creatine kinase isoform composition was determined by non-denaturing electrophoresis, immunoblotting, protein purification, and amino acid sequence analysis. The results demonstrate both B creatine kinase and mitochondrial creatine kinase proteins are present in the rectal gland, an isoform composition which is the same as in the mammalian kidney. By using a combination of chromatographic techniques, shark B creatine kinase was purified to homogeneity and partial sequence data was obtained from two cyanogen bromide peptide fragments. One of these fragments contains the active site and is identical at all sequenced residues with the corresponding region from the echinoderm sperm flagellar creatine kinase, and is 96% homologous with both chicken and rat B creatine kinase subunits. The other fragment corresponds to a region near the N-terminal of mammalian creatine kinases and is 89% homologous with B creatine kinase from chicken. The localization of these isoforms was examined by immunocytochemistry using subunit specific antisera. Mitochondrial creatine kinase and B creatine kinase immunoreactivity are detected in all tubules, and is restricted to the basal region of the cells, which is the site of the Na+/K(+)-ATPase. The conservation of creatine kinase isoform expression in excretory tissue, and the localization of creatine kinase immunoreactivity in the basal region of the tubule cells, demonstrate that subcellular compartmentation of B creatine kinase may underly the functional coupling of creatine kinase activity with sodium transport.
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PMID:Purification and localization of brain-type creatine kinase in sodium chloride transporting epithelia of the spiny dogfish, Squalus acanthias. 131 Sep 91

A smooth muscle plasma membrane vesicular fraction (PMV) purified for the (Ca2+/Mg2+)-ATPase has endogenous glycolytic enzyme activity. In the presence of glycolytic substrate (fructose 1,6-diphosphate) and cofactors, PMV produced ATP and lactate and supported calcium uptake. The endogenous glycolytic cascade supports calcium uptake independent of bath [ATP]. A 10-fold dilution of PMV, with the resultant 10-fold dilution of glycolytically produced bath [ATP] did not change glycolytically fueled calcium uptake (nanomoles per milligram protein). Furthermore, the calcium uptake fueled by the endogenous glycolytic cascade persisted in the presence of a hexokinase-based ATP trap which eliminated calcium uptake fueled by exogenously added ATP. Thus, it appears that the endogenous glycolytic cascade fuels calcium uptake in PMV via a membrane-associated pool of ATP and not via an exchange of ATP with the bulk solution. To determine whether ATP produced endogenously was utilized preferentially by the calcium pump, the ATP production rates of the endogenous creatine kinase and pyruvate kinase were matched to that of glycolysis and the calcium uptake fueled by the endogenous sources was compared with that fueled by exogenous ATP added at the same rate. The rate of calcium uptake fueled by endogenous sources of ATP was approximately twice that supported by exogenously added ATP, indicating that the calcium pump preferentially utilizes ATP produced by membrane-bound enzymes.
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PMID:Comparison of endogenous and exogenous sources of ATP in fueling Ca2+ uptake in smooth muscle plasma membrane vesicles. 131 Oct 20


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