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)

Some of the characteristics of the pyrophosphatase and ATPase activities studied in isolated cartilage matrix vesicles were found to be similar to those already reported for the solubilized and purified bone alkaline phosphatase. Thus, the pH optimum of the pyrophosphatase activity responded similarly to changes in the concentration of Mg2+, Ca2+, and PPi. Further, the ATPase activity was not activated by Ca2+ in the presence of an optimal Mg2+ concentration. It is proposed that a function of the alkaline phosphatase of matrix vesicles in vivo is to hydrolyze the substrates PPi, ADP, and ATP, which are known inhibitors of calcium phosphate precipitation.
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PMID:Pyrophosphatase and ATPase of isolated cartilage matrix vesicles. 1 78

An uncoupler of oxidative phosphorylation causes an instantaneous cessation of movement of bacteria Rhodospirillum rubrum in the presence and in the absence of oligomycin. It is concluded that such cessation is not due to a decrease in the ATP concentration but to the elimination of deltamicron-H+ by the uncoupler. The mobility of the bacteria does not practically change in the presence of acetate and is, to some extent, decreased after addition of valinomycin or penetrating cation of tetraphenyl phosphonium. Under a combined action of acetate and valinomycin the movement is depleted. It is concluded that both constituents of deltamicronH+-transmembrane difference of electric potentials and the pH gradient--may serve as energy sources for the bacteria movement. Inhibitory analysis data suggest that the bacteria movement may be maintained by any of the deltamicronH+ sources, e.g. light-dependent cyclic electron transfer, respiration, ATPase and membrane pyrophosphatase.
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PMID:[Electrochemical gradient of H+ ions as an immediate source of energy during bacteria movement]. 1 48

The effects of fixation with various concentrations of glutaraldehyde or formaldehyde, acetone or ethanol, and freeze-drying on 5 phosphatases of Eimeria tenella and chick kidney cell cultures were demonstrated in situ. Gultaraldehyde inactivated the phosphatases more than did the formaldehyde, but the effect of the combination of the 2 (Karnovsky's fixative) was greater than that of either glutaraldehyde or formaldehyde alone. The higher the concentration of aldehyde and the longer the duration of exposure, the greater the inactivation. The order of sensitivity to aldehyde fixation of the enzymes tested was glucose-6-phosphatase greater than thiamine pyrophosphatase greater than 5'-nucleotidase greater than adenosine triphosphatase greater than acid phosphatase. Cytologic detail was preserved more efficiently with glutaraldehyde than with formaldehyde. Optimal preservation of enzyme activity for cytochemistry was with 2% glutaraldehyde for 30 min or 2% formaldehyde for 1 hr for G-6-Pase, TPPase, and 5'-nucleotidase, and with 2% glutaraldehyde or 2% formaldehyde for 2 hr with ATPase and AcPase. Quenching with subsequent fixation in cold acetone or ethanol resulted in complete inactivation of G-6-Pase, TPPase, and 5'-nucleotidase; although cells fixed in this manner yielded large amounts of reaction product for ATPase and AcPase, the distribution was diffuse, and some of it appeared to be artifactual. Quenching with subsequent freeze-drying was unsatisfactory because nearly all of the cell layers rolled off the cover glasses.
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PMID:Effect of fixation on demonstration of phosphatases of Eimeria tenella grown in chick kidney cell cultures. 6 Dec 71

Recent results suggest consideration of a new concept for oxidative phosphorylation in which a prime function of energy is to bring about release of ATP formed at the catalytic site by reversal of hydrolysis. Data with submitochondrial particles include properties of an uncoupler insensitive Pi=HOH exchange, a rapid reversible formation of bound ATP in presence of uncouplers, and predictable patterns of 32-Pi incorporation into ATP in rapid mixing experiments. ADP is confirmed as the primary Pi acceptor in mitochondrial ATP synthesis, but with chloroplasts ADP is also rapidly labeled. Other findings with pyrophosphatase and with transport ATPase harmonize with the new concept. Measurements of the reversal of ATP cleavage and binding by myosin suggest that oxygen exchanges result from reversible cleavage of ATP to ADP and Pi at the catalytic site and that the principal free energy change in ATP cleavage occurs in ATP binding. Reversal of conformational changes accompanying ATP binding and cleavage is proposed to drive the actin filament in contraction. Thus energy transductions linked to ATP in both mitochondria and muscle may occur primarily through protein conformational change.
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PMID:Coupling of "high-energy" phosphate bonds to energy transductions. 12 70

Continuous sucrose density gradient subfractions from bovine adrenal medullary microsomes were found to accumulate 45-Ca-2+ in the presence of ATP and ammonium oxalate mainly in subfractions of intermediate density. (Na-++K-+)-ATPase (plasma membrane marker) and Ca-2+-ATPase activities were also concentrated in these intermediate subfractions but thiamine pyrophosphatase (Golgi apparatus marker) was not. NADH oxidase (endoplasmic reticulum marker) activity was distributed throughout all subfractions. 45-Ca-2+ accumulation in adrenal cortical microsomes was found to rise and fall in parallel with thiamine pyrophosphatase but not with (Na-++K-+)-ATPase or NADH oxidase activities. Accumulation of 45-Ca-2+ in membrane vesicles in these experiments suggests the existence of a calcium transfer mechanism in plasma membranes of the adrenal medulla but not adrenal cortex.
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PMID:Evidence for a plasma membrane calcium pump in bovine adrenal medulla but not adrenal cortex. 12 98

The localization of ATPase and thiamine pyrophosphatase in the digestive system of Ophiocephalus punctatus has been studied. In stomach ATPase is found in the free border of the mucosa, gastric glands, submucosal connective tissue nuclei and muscularis. Thiamine pyrophosphatase is localized only in the mucosa and gastric gland cells. In the intestine, pyloric caeca and rectum, ATPase is distributed along the brush border of the columnar epithelial cells, their nuclei and cytoplasm. Mild activity is also found in the nuclei of submucosa and muscularis. The activity is stronger in the intestine than in the other portions. Thiamine pyrophosphatase activity in these portions is restircted only to the goblet cells. In the liver ATPase activity is associated both with the cytoplasm and nucleus of the hepatic cells. Thiamine pyrophosphatase activity is maximum in the centro-lobular portion.
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PMID:Histochemical localization of adenosine triphosphatase and thiamine pyrophosphatase in the digestive system of a teleost fish, Ophiocephalus punctatus. 12 4

With increasing amounts of thiamine introduced into the intestines the extent of its absorption by the intestinal mucosa is shown to decline. The activity of thiamine-pyrophosphatase (KF 3.6.1.6) in the intestinal mucosa rises with absorption of physiological and large quantities of thiamine, whereas Na+-K+-activated ATPase (Kf 3.6.1.3) becomes activated only with absorption of physiological doses of vitamin B1. The participation of these enzymes in the regulation of the thiamine absorption in the intestines is suggested.
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PMID:[The activity of several enzymes of the mucous membrane of the intestine during thiamine absorption]. 13 34

1. The distributions of several enzymes and other marker components were examined after zonal centrifugations of whole homogenates from glucose-repressed Saccharomyces cerevisiae on sucrose and iso-osmotic Ficoll, and the composition and morphology of the fractions were investigated. 2. After high-speed zonal centrifugation most of the protein, acid and alkaline phosphatases, alkaline pyrophosphatase, adenosine monophosphatase, beta-fructofuranosidase, alpha-mannosidase, NADPH-cytochrome c oxidoreductase and an appreciable amount of phospholipid and sterol were non-sedimentable, i.e. were at densities below 1.09 (g/cm3). Most of the RNA was at p=1.06-1.08 in Ficoll and at p=1.09-1.11 in sucrose. 3. The bulk of the Mg2+-dependent adenosine triphosphatase (Mg-ATPase) was coincident with the main peak of phospholipid and sterol, at median density 1.10, which was also rich in smooth-membrane vesicles. In Ficoll, a minor peak of phospholipid and sterol at p-1.12-1.15 contained a smaller part of the oligomycin-insensitive Mg-ATPase and heavy membrane fragments. In sucrose, several minor peaks of Mg-ATPase were in the mitochondrial density range, and a peak of oligomycin-insensitive Mg-ATPase coincident with a minor peak of phospholipid and sterol at around p-1.25 contained heavy membrane fragments of high carbohydrate content, especially mannose. 4. Further purification of the oligomycin-insensitive Mg-ATPase containing membrane preparations was performed on Urografin gradients. 5. It is argued that the oligomycin-insensitive Mg-ATPase containing membranes are fragments of the plasma membrane, but have different densities because they contain different amounts of glycoprotein particles.
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PMID:Distribution of membranes, especially of plasma-membrane fragments, during zonal centrifugations of homogenates from glucose-repressed Saccharomyces Cerevisiae. 13 74

Histochemical localization of adenosine triphosphatase and thiamine pyrophosphatase in the digestive system of the teleost fish, Heteropneustes fossilis has been studied. In the stomach, ATPase activity is observed in the mucosa, gastric glands and muscularis. The activity is stronger in the muscularis. Very weak TPPase activity is localized only in the mucosa and gastric glands. In the intestinal mucosa ATPase activity is stronger especially, along the brush border. Mild activity is also found in the connective tissue network and their nuclei, muscularis and serosa. In the posterior portion of the intestine and rectum, the localization pattern is similar to that of intestine but the activity is weaker. TPPase activity in the intestine and rectum is restricted only to the goblet shaped mucus secreting cells. In the liver, strong activity of ATPase and moderate activity of TPPase are found in the cytoplasm as well as the nuclei of the hepatic cells.
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PMID:Distribution of adenosine triphosphatase and thamine pyrophosphatase in the digestive system of Heteropneustes fossils. 13 69

Three proteins possessing alkaline phosphatase activity were detected in a fraction of periplasmic material of Escherichia coli K-10 and its mutants with constitutive synthesis of alkaline phosphatase. They also showed acid phosphatase, pyrophosphatase and ATPase activities. Through the use of phosphatase-negative mutants it was shown that these proteins were the products of a single structural gene and therefore represented alkaline phosphatase isozymes. The numbers of enzyme isoforms and possibly the spectrum of their phosphohydrolase activities were controlled by exogenous orthophosphate and depended on the integrity of regulator genes for alkaline phosphatase.
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PMID:Metabolic and genetic control of isoenzyme spectrum of alkaline phosphatase in Escherichia coli. 14 52


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