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)

1. As a part of studies on the mechanism by which catecholamines are released from the nerve terminals, the synaptic vesicle fraction was isolated from bovine caudatolenticular nuclei and thalamus by differential centrifugation essentially according to the method of Kadota and Kadota (17). 2. Further centrifugation on a sucrose density gradient of the synaptic vesicle fraction by the method of Whittaker et al. (1) yielded white materials on the upper portion of 0.4 M sucrose, which consisted of vesicles averaging 600-800 A in diameter, and did not show Mg2+-dependent ATpase activity. On the other hand, the denser materials centering on 0.6 M sucrose, consisting of a mixture of microsomes and synaptic vesicles of 400-500 A diameter, showed an ATpase activity activated by either Mg2+ or Ca2+ but not inhibited by ouabain. 3. The white materials on 0.4 M sucrose were almost free of mitochondria, but they contained a large amount of non-heme iron, as reported elsewhere (2). Furthermore, the protein components analyzed on SDS-polyacrylamide gels were similar to those already reported for purified synaptic vesicles (3). 4. Based on these results, the white materials were assumed to be synaptic vesicles devoid of Mg2+-dependent ATPase activity.
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PMID:Synaptic vesicle fraction devoid of adenosine triphosphatase activity from bovine caudatolenticular nuclei and thalamus. 14 20

A myosin B-like protein was extracted from the alga Nitella flexilis. SDS-polyacrylamide gel electrophoresis revealed the presence of myosin heavy chain and actin as the main components. At high ionic strength, its ATPase [EC 3.6.1.3] reaction was activated by EDTA or Ca2+ and inhibited by Mg2+. At low ionic strength, superprecipitation was induced by the addition of ATP. Myosin was purified from Nitella myosin B. The molecular weight of the heavy chain of Nitella myosin, estimated by SDS-gel electrophoresis, was slightly higher than that of skeletal muscle myosin. At low ionic strength, Nitella myosin aggregated to form bipolar filaments about 0.2 micron long. At high ionic strength, its ATPase reaction was activated by EDTA or Ca2+, and inhibited by Mg2+. The Mg2+-ATPase reaction of Nitella myosin was activated by skeletal muscle F-actin.
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PMID:Identification of myosin in Nitella flexilis. 14 21

Membrane-bound Ca or Mg of sarcoplasmic reticulum fragments were removed by treating the membrane with EDTA or an acidic solution, and the changes in the enzymatic activities of sarcoplasmic reticulum fragments induced by these treatments were examined. With the decrease in the amount of membrane-bound Ca below 1-3-10(-8) mol/mg protein, it was demonstrated that the activity of (Ca2+ + Mg2+)-ATPase transiently increased and then diminished, that the Ca-uptake and phosphoenzyme formation declined gradually, and that the activity of Mg2+-ATPase was affected to a less extent. Sodium dodecyl sulfate-gel electrophoretic patterns of peptides from the metal-deficient membranes were the same as those of the untreated material. The level of the phosphoenzyme formation of the metal-deficient membrane was restored by increasing the amount of membrane-bound Ca, but not by increasing the amount of membrane-bound Mg.
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PMID:The formation of phosphoenzyme of sarcoplasmic reticulum. Requirement for membrane-bound Ca2+. 14 31

Immediately after the death of rabbits and at different times within 48 hours, we took out a part of the psoas muscle, from which we made myofibrilar preparations. The carcasses providing the muscle samples were held at two different temperatures. One group was held for 48 hours at 25 degrees C, imitating room temperature. The other group was held for 12 hours at 25 C degrees and at 25 C degrees and 12 hours at 10 C degrees, imitating daily temperature changes. Each myofibrilar sample was subjected to SDS-polyacrylamide gel electrophoresis. In addition we determined the Ca++ activated and the EGTA inhibited ATPase specific activity of the myofibrils. We found that within 48 hours the myofibrilar proteins were subjected to some characteristic proteolytic changes, which were dependant on the environmental temperature. The most interesting change was found in carcasses held constantly at 25 C degrees for 48 hours, where the EGTA inhibited ATPase activity was increased to about seven times its initial value, reflecting impairment of the troponin complex.
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PMID:[The post mortem alterations of myofibrilar proteins and adenosintriphosphatase activities of the skeletal muscles (author's transl)]. 14 81

1. Morphologic as well as biochemical alterations in chronic ischemic myocardial tissue without infarction were studied in dogs utilizing the Ameroid constrictor. 2. Serum creatine kinase activity elevated at around three weeks after placing the Ameroid constrictor around the circumflex branch of the left coronary artery suggestive of myocardial tissue injury followed by the initial activation caused by surgery. 3. Subendocardial proliferation of connective tissue was observed in about 60% of the experiments, but the middle and the subepicardial muscles were morphologically intact. 4. The marked increase in glycogen particles was observed in the subendocardial muscle cells in most of the experiments, and mild features of myocardial cellular necrosis were found in approximately 60% of the experiments. 5. ATPase activities of the structural proteins as well as sarcoplasmic reticulum in the ischemic myocardium shoed relatively higher values than those in the non-ischemic myocardium. However, no substructural changes were observed in SDS gel electrophoresis in both the fractions. 6. The alterations in the chronic myocardial ischemia are supposed to be essentially the same as those in myocardial necrosis followed by acute coronary occlusion.
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PMID:Morphologic and biochemical studies on the experimental chronic ischemic myocardium with the Ameroid constrictor. 14 55

A plasma membrane fraction of HeLa S3 cells, consisting of ghosts, is characterized more fully. A simple procedure is described which permits light and electron microscope study of the plasma membrane fraction through the entire depth of the final product pellet and through large areas parallel to the surface. Contamination by nuclei is 0.14%, too little for DNA detection by the diphenylamine reaction. Contamination by rough endoplasmic reticulum and ribosomes is small, a single ghost containing about 3% of the RNA in a single cell. Mitochondria were not encountered. Electron microscopy also shows (a) small vesicles associated with the outer surface of the ghosts, and (b) a filamentous web at the inner face of the ghost membrane. Sodium dodecyl sulfate (SDS)-polyacrylamide gel analysis shows that of the many Coomassie Blue-stained bands two were prominent. One, 43,000 daltons, co-migrated with purified rabbit muscle actin and constituted about 7.5% of the plasma membrane protein. The other major band, 34,000 daltons, was concentrated in the plasma membrane fraction. Two major glycoproteins detected by autoradiography of [14C]fucose-labeled glycoproteins on the gels, had apparent molecular weights of 35,000 daltons and 32,000 daltons. These major bands did not stain with Coomassie Blue. There were many other minor glycoprotein bands in the 200,000- to 80,000-dalton range. Ouabain-sensitive, Na+, K+-adenosine triphosphatase (ATPase) activity of the ghost fraction is purified 9.1 (+/- 2.2) times over the homogenate; recover of the activity is 12.0 (+/- 3.8%) of the homogenate. Enrichment and recovery of fucosylglycoprotein parallel those for ouabain-sensitive Na+, K+-ATPase activity. Fucosyl glycoprotein is recovered more than the enzyme activity in a smooth membrane vesicle fraction probably containing the bulk of plasma membrane not recovered as ghosts.
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PMID:Further characterization of HeLa S3 plasma membrane ghosts. 14 66

Ca2+ regulation of molluscan actomyosin adenosine triphosphatase is known to be associated with the myosin molecule. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, however, also suggests the possible presence of troponin, a thin-filament-linked Ca2+-regulatory complex. In the present study, scallop troponin and tropomyosin were prepared and complexed with rabbit actin; the resulting synthetic thin filaments form a Ca2+-dependent actomyosin adenosine triphosphatase with Ca2+-insensitive rabbit myosin, indicating that the troponin in scallops is potentially functional. Scallop troponin I was isolated and mixed with chicken troponin C and troponin T, forming a functional hybrid troponin complex, indicating that scallop and vertebrate troponins may act by a common mechanism. Densitometry of sodium dodecyl sulphate/polyacrylamide gels reveals that in synthetic thin filaments there are larger amounts of troponin than are present in native thin filaments. Amounts present in the intact muscle were not determined.
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PMID:Troponin-like proteins from muscles of the scallop, Aequipecten irradians. 14 88

Membrane-bound and free polyribosomes were isolated from skeletal muscle of neonatal rats and messages were translated in a rabbit reticulocyte lysate treated with Ca2+ -dependent nuclease to reduce endogenous messenger translation. Newly synthesized calsequestrin and adenosine triphosphatase (ATPase) sere isolated by antibody precipitation, followed by separation of the precipitates in SDS-polyacrylamide gels. Radioactivity in calsequestrin and the ATPase were counted in gel slices. Calsewuestrin and the ATPase were both found to be synthesized on membrane-bound polyribosomes. Since calsequestrin is a glycoprotein, localized in Golgi regions in early stages of muscle cell differentiation, it is probable that its synthesis follows the pathway for synthesis of secreted proteins except that its destination is the luminal space of a cellular organelle. The disposition of the ATPase during synthesis is, as yet, unknown.
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PMID:Assembly of the sarcoplasmic reticulum. Synthesis of calsequestrin and the Ca2+ + Mg2+ -adenosine triphosphatase on membrane-bound polyribosomes. 14 86

ATPase (ATP phosphohydrolase, EC 3.6.1.3) activity was shown in the soluble fraction of rat liver micochondria. Two molecular forms (ATPase 1 and 2) were isolated. ATPase 1 has already been studied. The present paper deals with the purification method of ATPase 2 which was achieved by the following steps: (NH4)2SO4 precipitation. DEAE-cellulose chromatography, hydroxyapatite chromatography, Sephadex G100 filtration and AMP-Sepharose affinity chromatography. The purified protein was characterized by bidimensional polyacrylamide gel electrophoresis. Molecular weight evaluated by SDS-polyacrylamide gel electrophoresis and Sephadex G100 gel filtration was found to be 61 500 +/- 3000.
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PMID:Purification of a soluble ATPase from rat liver mitochondria by AMP-Sepharose affinity chromatography. 15 Aug 61

1. Influence of ischemia on the biochemical properties of the sarcoplasmic reticulum (SR) was studied in the experimental myocardial infarction in the dog. 2. Ca2+ -uptake rate of SR decreased at around 90 minutes after coronary occlusion. This reduction was roughly in parallel with the reduction in the Ca+ -Mg2+ -stimulated ATPase activity. However, Ca2+ -binding rate of SR was kept within the range of that of the non-infarcted tissue through the time course of myocardial infarction. 3. Ca2+ -Mg2+ -stimulated ATPase activity decreased at around 3 hours after coronary occlusion to about 50% of that of the non-infarcted portion. 4. In SDS gel electrophoresis, the protein band with the largest molecular weight among three major components decreased at 3 hours after coronary occlusion, which is suggestive of ATPase. At 48 hours after coronary occlusion, the protein with the smallest molecular weight in the major proteins also decreased. 5. Ca2+ -uptake rate, Ca2+ -Mg2+ -stimulated ATPase activity and the substructural changes return to the normal level and pattern at around 28 days after coronary occlusion.
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PMID:Studies of the cardiac sarcoplasmic reticulum in myocardial infarction. 15 53


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