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)

Ureaplasma urealyticum cells were lysed by osmotic shock or by digitonin. The membrane fraction contained four to ten times as much protein as the cytoplasmic fraction. These values are in large excess of those reported for classical mycoplasmas, suggesting that the Ureaplasma membrane fraction was heavily contaminated with proteins derived from the growth medium. The U. urealyticum urease activity was localized in the cytoplasmic fraction, whereas the adenosine triphosphatase activity was localized in the membrane fraction. Significant urease activity could be detected also in nonviable cells. Urea, at concentrations above 0.25 M, was mycoplasmastatic to Acholeplasma laidlawii, Mycoplasma hominis, and U. urealyticum, so that the Ureaplasma urease did not afford preferential protection against urea toxicity. The intracellular localization of the urease would be expected to release ammonia from urea in the cytoplasm. The ammonia will take up protons to become ammonium ions. It can be hypothesized that the intracellular NH4+ plays a role in proton elimination or acid-base balance, which might be coupled to an energy producing ion gradient and/or transport mechanisms.
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PMID:Localization of enzymes in Ureaplasma urealyticum (T-strain mycoplasma). 1 80

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

The properties of a Ca2+ activated adenosine triphosphatase shown to be present in homogenates of purified rat peritoneal mast cells were investigated. The enzyme was activated by Ca2+, Mg2+, and to a lesser extent by Mn2+ and Co2+. Ca2+ alone was necessary for full activity and the further addition of Mg2+ did not have any effect. The chelating agents EGTA (ethanedioxybis(ethylamine)tetra-acetate) and EDTA completely inhibited the reaction. The pH optimum was 7.8. Reduced glutathione, cysteine, dithiothreitol, N-ethylmaleimide, urea, ADP, NaF, increasing ionic strength and Triton X-100 all inhibited the reaction. On subcellular fractionation of mast-cell homogenates by density-gradient centrifugation, the distribution of Ca2+ activated adenosine triphosphatase resembled that of 5'-nucleotidase, but differed from that of the other markers used, suggesting localization in the plasma membrane. Further experiments indicated that the enzyme is present on the external surface of the plasma membrane.
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PMID:Characterization of calcium-ion-activated adenosine triphosphatase in the plasma membrane of rat mast cells. 13 82

1. The fluorescence and circular dichroism of four homogeneous preparations of ATPase (adenosine triphosphatase) from Micrococcus lysodeikticus differing in molecular structure and enzymic properties were examined at pH 7.5 and 25 degrees. Emission was maximum at 325 and 335 nm and the relative intensities at these wavelengths may be used to characterize the different ATPase preparations. The circular-dichroism spectra exhibited negative extrema at 208 and 220 nm, and the relative value of the molar ellipticity at these wavelengths was also different for each molecular form of the enzyme. 2. The four preparations undergo two consecutive major unfolding transitions in guanidinium chloride (midpoints at 0.94 and 1.5 M denaturant), with concomitant destruction of the quaternary structure of the protein. A comparatively minor alteration in the ATPase structure also occurred in 0.05-0.2M-guanidine and led to complete inactivation of the enzyme. The inactivation and the first unfolding transition were reversible by dilution of the denaturant; the transition with midpoint at 1.5M-guanidine was irreversible. 3. Similar results were obtained in urea, except that the successive transitions had midpoints at concentrations of denaturant of 0.4, 2.0 and 4.5M. Low concentrations of urea caused a noticeable activation of the enzyme activity and alterations of the electrophoretic mobility of the ATPase. 4. A model is proposed in which one of the major subunits, alpha, is first dissociated and unfolded reversibly by the denaturants, followed by the irreversible unfolding and dissociation of the other major subunit, beta, from subunit delta and/or the components of relative mobility 1.0 in dodecyl sulphate/polyacrylamide-gel electrophoresis (rho).
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PMID:Optical properties and denaturation by guanidinium chloride and urea of the adenosine triphosphatase of Micrococcus lysodeikticus. A comparison of four molecular forms of the enzyme. 13 87

Hydrophobic agents, e.g. methanol, ethanol, isopropanol, acetone and dioxane were shown to induce irreversible inactivation of Na+, K+-adenosine triphosphatase beginning with their concentrations of 20 to 35%, whereas dimethyl sulphoxide exerted similar effect only at concentration of 50% and higher. Urea also irreversibly inactivated Na+, K+-adenosine triphosphatase, beginning with a concentration of about 20%. It was found that, dimethyl sulphoxide contrary to the other hydrophobic agents studied, protected Na+, K+-adenosine triphosphatase against the inactivating (denaturing) action of urea. The highest stabilizing effect of dimethyl sulphoxide was displayed at concentrations from 20 to 30%.
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PMID:[Stabilization of Na+, K+-adenosine triphosphatase by dimethyl sulfoxide under inactivation by urea]. 14 22

Navicula pelliculosa and an associated Flavobacterium sp. were isolated from the epiphyton of Scirpus maritimus, an emergent macrophyte growing in a brackish drainage dyke. Both micro-organisms possessed active transport systems for glucose uptake. In N. pelliculosa the transport system was fully induced in the dark in the absence of glucose, and subsequently inactivated when transferred to the light in the absence of the substrate. The presence of glucose during the dark induction period prevented the achievement of maximum specific activity of the transport system, while incubation at a high light intensity with or without the presence of the substrate resulted in a very marked inhibition of glucose uptake. Inhibition in the light was partially offset by blocking photosynthetic electron flow with 3'(3,4 dichlorophenyl)1'1' dimethyl urea. The transport system accumulated 3-O-methyl glucose against a concentration gradient and was highly specific for glucose as there was no competition by most of the other sugars tested. However, 6-deoxyglucose was taken up instead of glucose and this suggested that glucose was transported in a non-phosphorylated state, whereas inhibition of glucose transport activity with dicyclohexylcarbodimide implicated the involvement of an adenosine triphosphatase on the cell membrane. Inhibitors of oxidative phosphorylation tetrachlorosalicylaniline and carbonylcyanide m-chlorophenylhydrazone also inhibited glucose transport activity. The affinity of the diatom for glucose was greater than that shown by the bacterium, but the Km for glucose transport, 1.5x10-5M was too high to allow effective removal of glucose at in situ concentrations.
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PMID:A description of glucose uptake in Navicula pelliculosa (Breb) Hilse including a brief comparison with an associated Flavobacterium sp. 96 66

Ethanol (3%) decreases the potential difference and short-circuit current across the isolated frog skin in chloride Ringer's solution. Unidirectional fluxes of Na and Cl indicate that the drop in short-circuit current is due to an inhibition of the sodium influx. However, ethanol had no effect on the electrical parameters or sodium fluxes, when the frog skin was bathed in chloride-free solutions on both sides or the outside alone. The ethanol response is anion-dependent. In addition, chloride-free media in the inside bathing solution reduced the short-circuit current, indicating a sodium transport pathway which is dependent on chloride and confirming previous data in the literature. Other anions such as sulfate and nitrate could not substitute for chloride. The vasopressin-induced natriferic response and the ethanol effect were found to work independently of each other and different pathways of action are suggested for these agents. The intracellular sodium content of the isolated frog skin epithelium increased and potassium decreased in the presence of the Na-K adenosine triphosphatase inhibitor, ouabain, whereas ethanol or amiloride had no effect. The oxygen consumption of the isolated frog skin was unaffected by up to 10% ethanol. A general metabolic action is probably thus not mediating the response. Urea, in iso-osmotic concentrations to the ethanol, did not mimic its effect. Tritiated water fluxes (in the absence of an osmotic gradient) were reduced by 30% in the presence of 3% ethanol. It is suggested that ethanol may impede the flow of water across frog skin by a physicochemical interaction with membrane pores and the water molecules. The permeability coefficient (Ktrans) for ethanol was found to be 10 times smaller than the Ktrans for water.
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PMID:Effects of ethanol on the permeability of frog skin. 108 5

Arginase activity of erythrocyte membrane fragments has been determined in normal subjects and in two groups of uremic patients: 1) those having a blood urea concentration of 100 mgm/100 ml or higher and with an elevated erythrocyte sodium concentration and 2) patients with a blood urea concentration of 100 mgm/100 ml and higher and a normal erythrocyte sodium concentration. No statistically significant difference was detected between the normal subjects and the uremic patients. It is concluded, therefore, that the effect of uremia on the magnesium dependant, Na and K activated adenosine triphosphatase of erythrocyte membranes is not applicable to all enzymes of the erythrocyte.
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PMID:Arginase activity of human erythrocyte ghosts in uremia. 123 23

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

A microsomal adenosine triphosphatase (ATPase) that requires both sodium and potassium ions is thought to be identical with, or an integral part of, the active cation transport system located in cell membranes. Attempts to isolate and purify (Na(+) + K(+))-ATPase have met with limited success because solubilization of microsomal protein causes partial, if not complete, loss of enzymatic activity. We now report the isolation from rat kidney microsomes of proteins which, though enzymatically inactive, could still be identified as components of the (Na(+) + K(+))-ATPase system. Phosphoproteins known to be intermediates in the hydrolysis of ATP by (Na(+) + K(+))-ATPase were prepared by incubating rat kidney microsomes with gamma-labeled ATP(33) in the presence of sodium or with P(32)-orthophosphate in the presence of ouabain. After the P(32)- and P(33)-labeled microsomes had been dissolved in phenol-acetic acid-urea, the resultant solutions were mixed and subjected to polyacrylamide gel electrophoresis. The radioactivity from both phosphorus isotopes was found almost exclusively in one of the resultant 21 protein bands. In contrast, the radioactive protein from DFP(32)-labeled microsomes moved slightly faster than the radioactive protein from microsomes labeled with P(33)-orthophosphate in the presence of ouabain. DFP inhibits (Na(+) + K(+))-ATPase by reacting with a nucleophilic site at or near the active site. These results suggest that while a single protein component of (Na(+) + K(+))-ATPase accepts the terminal phosphate from ATP, the final splitting of this phosphoprotein intermediate may be catalyzed by nucleophilic sites on a second protein.
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PMID:Identification of components of (Na+ plus K+)-adenosine triphosphatase by double isotopic labeling and electrophoresis. 424 29


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