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)

Two types of canine cardiac myosins, from the free wall of the left ventricle and from the free wall of the right ventricle, were compared with canine skeletal muscle myosin from gastrocnemius. For K+ -activated myosin the Vmax values in mumoles of Pi/mg.min were: right ventricle, 0.57 +/- 0.02; left ventricle, 0.72 +/- 0.09; gastrocnemius, 0.92 +/- 0.04. For Ca++ -activated myosin the Vmax values were: right ventricle, 0.32 +/- 0.04; left ventricle, 0.42 +/- 0.03; gastrocnemius, 0.52 +/- 0.02; (p greater than 0.01 for all defferences). For all three types of tissues the Vmax values for NH4+ -activated myosin were the same (2.30 +/- 0.11). Corresponding to kinetic changes there were significant changes in the proportion and type of myosin subunits. In the two cardiac ventricles where heavy chains were immunologically identical, 81% of the total nitrogen of right ventricular myosin was present in the heavy chains whereas in left ventricular myosin 90% of the total nitrogen of myosin was present in the heavy chains. Quantifications were made on polyacrylamide gels were dye binding was directly related to nitrogen concentration for each of the myosin chains. In canine skeletal muscle gastrocnemius where the myosin heavy chains were immunologically nonidentical with those of cardiac myosin, 87% of the total nitrogen was present in the heavy chains. The data suggest that there are 2 moles of myosin light chains per mole of myosin heavy chains in right ventricular myosin where the adenosine triphosphatase (ATPase) activity is low and 1 mole of myosin light chains per mole of myosin heavy chains in left ventricula myosin where ATPase activity is elevated; for skeletal muscle myosin there were 1.5 moles of myosin light chains per mole of myosin heavy chains. Proportion of myosin light chain C1 to light chain C2 was the same in both left and right ventricular myosin. In skeletal muscle myosin the proportion of light chain C1 to light chain C2 was significantly different from that of cardiac tissue. It appears that the proportion of myosin light chain C1 to light chain C2 is directly related to the type of myosin heavy chain present since the immunologically identical heavy chains of cardiac tissue were immunologically nonidentical with those of skeletal muscle myosin.
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PMID:Comparative analyses of skeletal and cardiac myosins. 12 33

The toxic effects of imidocarb diproprionate (3,3'-bis [2 imidazolin-2yl]-carbanilde diproprionate) were evaluated in adult goats given (intramuscular injection) a lethal dose (6.75 mg/kg). The immediate clinical signs of toxicosis were transient excessive salivation and diarrhea. Anorexia, dyspnea, recumbency, and death occurred between postinjection days (PID) 4 and 8, during which time 7 goats died and 4 moribund goats were euthanatized. There were marked increases in mean serum urea nitrogen concentration and significant increases in serum glutamic oxalacetic transminase activity and in the mean number of circulating neutrophils after PID 4. Renal hyperemia and enlargement were evident by PID1. Serosanguineous fluid in the trachea and major bronchi, pulmonary congestion and edema, hydrothorax, hydroperitoneum, and less frequently hydropericardium were observed on and after day 4. Microscopic renal tubular lesions rapidly progressed from pyknotic epithelial nuclei observed at 6 and 12 hours to acute tubular necrosis of epithelium of the proximal convoluted tubules on days 1 and 2. Pulmonary congestion and edema; hemorrhage into alveoli, bronchioles, and bronchi; and intracytoplasmic lipid vacuoles within the hepatocytes in the periacinar zones of the hepatic lobules were observed on or after day 4. Succinic dehydrogenase and adenosine triphosphatase activities decreased progressively in the epithelial cells of the proximal convoluted tubules. The decreases in cellular enzymatic activity occurred shortly after the appearance of microscopic lesions in the tubular epithelium.
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PMID:Clinical, histologic, and histochemical study of imidocarb diproprionate toxicosis in goats. 13 83

In combination with the Mo-Fe protein of nitrogenase from Klebsiella pneumoniae, the Fe protein of nitrogenase from Clostridium pasteurianum forms an active enzyme with novel properties different from those of either of the homologous nitrogenases. The steady-state rates of reduction of acetylene and H+ are 12% of those of the homologous system from C.pasteurianim. Acetylene reductase activity exhibited an approx. 10min lag at 30 degrees C before the rate of reduction became linear, consistent with a once-only activation step being necessary for acetylene reduction to occur. No such lag was observed for H2 evolution. The activity with N2 as a reducible substrate was very low, implying that acetylene reductase activity is not necessarily an accurate indication of nitrogen-fixing ability. This is of particular relevance to studies on mutant and agronomically important organisms. Stopped-flow spectrophotometric studies showed unimolecular electron transfer from the Fe protein to the Mo-Fe protein to occur at the same rate (k2 = 2.5 X 10(2)s-1) and with the same dependence on ATP concentration (apparent KD = 400 muM) as with the homologous Klebsiella nitrogenase. However, an ATP/2e ratio of 50 was obtained for H2 evolution, indicating that ATP hydrolysis had been uncoupled from electron transfer to substrate. These data indicate that ATP has at least two roles in the mechanism of nitrogenase action. The combination of the Mo-Fe protein of nitrogenase of C.pasteurianim and the Fe protein of K.pneumoniae were inactive in all the above reactions, except for a weak adenosine triphosphatase activity, 0.5% of that of the homologous K.pneumoniae system.
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PMID:Nitrogenases from Klebsiella pneumoniae and Clostridium pasteurianum. Kinetic investigations of cross-reactions as a probe of the enzyme mechanism. 13

An adenosine triphosphatase (ATPase) mutant of Bacillus megaterium was isolated and characterized. This mutant (designated A37) was unable to grow on nonfermentable carbon sources and possessed less than 5% of the wild-type ATPase activity. Oxygen uptake by the mutant was comparable to that in the wild type. Sporulation in the wild type occurred in both glucose- and nitrogen-limiting media; however, A37 sporulated only in the nitrogen-limiting medium. The inability of A37 to sporulate in glucose-limiting medium seemed to be due to insufficient adenosine 5'-triphosphate (ATP) levels during the sporulation stages. Fructose, which can generate ATP via substrate-level phosphorylation, is equally efficient in stimulating ATP synthesis in the wild type and A37. Malate-stimulated ATP synthesis in the wild type was shown to have many characteristics associated with oxidative phosphorylation and was absent in the mutant. These data suggest that the ATPase deficiency results in the loss of oxidative phosphorylation.
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PMID:Bacillus megaterium mutant deficient in membrane-bound adenosine triphosphatase activity. 14 49

Male guinea pigs were exposed to nitrogen dioxide (2 mg/m3) during 180 days (8 hours a day). Long-term exposure induced thickening of the corneal layer of the epidermis as well as inflammatory infiltrations in the proper skin. The following enzymes were estimated histochemically in skin samples of experimental and control animals: succinic dehydrogenase, NADH2-tetrazolium reductase, lactate dehydrogenase; alkaline phosphatase, acid phosphatase and adenosine triphosphatase. Chronic exposrue stimulated a decrease of NADH2-tetrazolium reductase in the epidermis and connective tissue components of proper skin and marked positive reaction of lactate dehydrogenase in epidermal cells and hair follicles. Increase of a diffuse reaction on adenosine triphosphatase in smooth muscles of the skin was found also in exposed animals.
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PMID:Histopathological and histochemical studies of the skin of guinea pigs after long-term exposure to nitrogen dioxide. 14 74

A series of 2-[(2-imidazolylsulfinyl)methyl]anilines (2) having various substituents on their imidazole and aniline rings was synthesized and examined for their H+/K(+)-ATPase (adenosine triphosphatase) inhibitory effects and antisecretory activity against histamine-stimulated gastric acid secretions in Heidenhain pouch dogs. Although substitutions on the imidazole ring did not enhance biological activity, substitutions on the aniline ring by electron-donating substituents potently enhanced the enzyme inhibitory activity and also showed an inhibitory effect on histamine-stimulated gastric acid secretion after oral administration. In particular, the in vitro activity of the dimethyl (2u--w) and trimethyl (2ac) derivatives was about 10 times that of omeprazole. Also, 4-methyl (2k), 4-methoxy-5-methyl (2y) and 3,5-dimethyl-4-methoxy (2ab) derivatives showed a potent antisecretory effect of more than 80% after oral administration at 6 mg/kg. Although these aniline derivatives have relatively low stabilities in aqueous solution, replacement of the isobutyl group at the aniline nitrogen atom with N-(2-methoxyethyl) group enhanced the stability.
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PMID:Synthesis and structure-activity relationships of substituted 2-[(2-imidazolylsulfinyl)methyl]anilines as a new class of gastric H+/K(+)-ATPase inhibitors. II. 131 87

The effect of preventive and therapeutical function of Chinese herbs compound prescription Jian-Pi Yi-qi Li-Shui decoction (JPYQLSD) on cisplatin (DDP) and nephrotoxicity of rat. It was carried out that the prescription JPYQLSD had notable result in reducing content of serum urea nitrogen, glucosaminidase, beta 2-microglobulin of the rats (P < 0.05). JPYQLSD also could alleviate inhibition on activity of adenosine triphosphatase (ATP-ase). Pathological examination revealed the protective effect of the JPYQLSD on kidneys of rats. It suggested that JPYQLSD has a good effect on preventive and therapeutical function of Cisplatin (DDP) nephrotoxicity. The mechanism of JPYQLSD was to regulate the energy metabolism of rats.
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PMID:[Effect of preventive and therapeutical function of jian-pi yi-qi li-shui decoction on cisplatin nephrotoxicity in rats]. 133 69

New growth of extraocular muscle has been demonstrated in degenerating peripheral nerve autografts implanted between two extraocular muscles. This suggests that extraocular muscle may be lengthened for therapeutic purposes if a suitable matrix can be found to support this new growth. Investigators of peripheral nerve regeneration have found that the basal lamina of freeze-killed skeletal muscle remains intact and supports axonal regeneration. This study was designed to investigate the feasibility of inducing regenerative growth of extraocular muscle in freeze-treated extraocular muscle autografts. In six beagles the inferior oblique muscle was removed from both orbits, frozen in liquid nitrogen, and allowed to thaw at room temperature. The freeze-thaw cycle was repeated. The freeze-treated grafts were then sewn in an end-to-end fashion between the cut end of the lateral rectus and the globe. At both 4 and 8 weeks postoperatively, three dogs were killed, and the grafts were removed from both orbits. These were prepared for light and electron microscopic examination. This revealed robust growth of mature-appearing, innervated muscle fibers in the proximal graft that could be differentiated by adenosine triphosphatase histochemistry. Rare, immature fibers were seen in the distal graft. These results demonstrate that freeze-treated extraocular muscle autografts support regenerative growth of extraocular muscle.
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PMID:Extraocular muscle regeneration in freeze-treated extraocular muscle autografts. 198 98

The major biological functions of S-adenosyl-L-methionine (SAMe) include methylation of various molecules (transmethylation) and synthesis of cysteine (trans-sulphuration). A stable double salt of SAMe has been found to be effective in intrahepatic cholestasis. The mechanism of its therapeutic effect is not fully understood but presumably involves methylation of phospholipids. Methylation of plasma membrane lipids may affect membrane fluidity and viscosity, which modulate the activities of a number of membrane-associated enzymes, for example, the activity of enzymes involved in Na+/Ca++ exchange (e.g. sarcolemmal vesicles), Na+/K+ adenosine triphosphatase (ATPase) [e.g. hepatocyte plasma membranes], and Na+/H+ exchange (e.g. plasma membranes of colonic cells). Recently, patients with cirrhosis were shown to have an acquired metabolic block in the hepatic conversion of methionine to SAMe. These patients, when administered conventional elemental diets, develop abnormally low plasma concentrations of cysteine and choline, 2 nonessential nutrients present in low concentrations in most elemental diets. These low concentrations probably reflect systemic deficiencies attributable to reduced endogenous syntheses of cysteine and choline caused by limited availability of hepatic SAMe. Such cirrhotic patients are often in negative nitrogen balance and have abnormal hepatic functions, which are corrected by cysteine and choline supplements. Noncirrhotic patients on parenteral elemental diets also become deficient in cysteine and choline. Consequently, these patients may require SAMe as an essential nutrient to normalise their overall hepatic transmethylation and trans-sulphuration activities.
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PMID:Biochemistry and pharmacology of S-adenosyl-L-methionine and rationale for its use in liver disease. 208 85

Growth of cells of the potentially zoopathogenic fungus Basidiobolus haptosporus on a nutritionally defined medium with xanthine or urate as the nitrogen source results in greatly increased populations of microbodies. Modified Gomori procedures at the electron microscopic level suggested the single limiting membrane (and in some cases the granular matrix) of immature microbodies to be the exclusive subcellular locale(s) of alkaline phosphatase, 5'-nucleotidase and nucleoside diphosphatase activities. When grown in the presence of low inorganic phosphate, additional alkaline phosphatase activity was further identified cytochemically at and along profiles of endoplasmic reticulum and on inclusions previously described as "double-membraned vesicles". Cytochemical localization of acid phosphatase at microbody membranes was minimal if not ambiguous; Mg++-dependent adenosine triphosphatase and glucose-6-phosphatase were not identified at these locales. Quantitative biochemical estimates of alkaline phosphatase activity levels in particulate fractions initially increased with age of cells, perhaps as a function of the cultural induction and marked increase in immature microbody populations. We suggest that this enzyme may participate in some manner with protein translocation mechanisms associated with microbody biogenesis, ontogeny, and/or physiological function.
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PMID:Electron cytochemical demonstration of phosphatase activity with microbody membranes of Basidiobolus haptosporus. 282 62


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