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)

Degeneration of testis has been observed after administration of Iodine-125 in potassiumperchlorate treated rats. Histological damage is associated with loss of DNA, RNA, acid phosphatase, total adenosine triphosphatase (ATPase) and Na/K dependent ATPase. Iodine-125 induced atrophic testis shows higher content of sodium and lower levels of potassium as compared to control testis. Damage of testis by Iodine-125 has been compared with atrophied testis, following gamma irradiation earlier reported. Auger effect due to Iodine-125 decay and transmutation at the sites of nuclei and plasma membrane of germinal cells seems to be the possible explanation for testicular damage caused by Iodine-125.
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PMID:Biological damage in testis by iodine-125 in partially blocked thyroid of rats. 19 64

1. A microsomal fraction from ox cerebral cortex catalysed [(14)C]ADP-ATP exchange at a speed similar to that at which it liberated P(i) from ATP in the presence of Na(+), K(+) and Mg(2+). 2. Repeated washing the fraction with MgATP solutions solubilized most of the exchange activity and left the adenosine triphosphatase insoluble and little changed in activity. The exchange activity was accompanied by negligible adenosine-triphosphatase activity and was enriched by precipitation at chosen pH and by DEAE-Sephadex. At no stage was its activity affected by Na(+), K(+) or ouabain. 3. The washed microsomal fraction was exposed to a variety of reagents; a sodium iodide-cysteine treatment increased both adenosine-triphosphatase and exchange activities, as also did a synthetic zeolite. Preparations were obtained with exchange activities less than 3% of their Na(+)-plus-K(+)-stimulated adenosine-triphosphatase activity. Some contribution to the residual exchange activity was made by an adenylate kinase. 4. Thus over 95% of the microsomal ADP-ATP-exchange activity does not take part in the Na(+)-plus-K(+)-stimulated adenosine-triphosphatase reaction. Participation of some of the residual 3% of the ADP-ATP-exchange activity has not been excluded, but there appears no firm evidence for its participation in the adenosine triphosphatase; the bearing of this conclusion on mechanisms proposed for the Na(+)-plus-K(+)-stimulated adenosine triphosphatase is indicated.
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PMID:Separation of adenosine diphosphate--adenosine triphosphate-exchange activity from the cerebral microsomal sodium-plus-potassium ion-stimulated adenosine triphosphatase. 422 77

1. An ATPase (adenosine triphosphatase) preparation obtained from pig brain microsomes by treatment with sodium iodide showed four apparently different ouabain-sensitive activities under various conditions. They were (a) ouabain-sensitive Mg(2+)-stimulated ATPase, (b) K(+)-stimulated ATPase, (c) (Na(+),K(+))-stimulated ATPase and (d) Na(+)-stimulated ATPase activities. 2. These activities showed the same substrate specificity, ATP being preferentially hydrolysed and CTP slightly. AMP was not hydrolysed. 3. These activities were inhibited by low concentration of ouabain. The concentration producing 50% inhibition was 0.1mum for ouabain-sensitive Mg(2+)-stimulated ATPase, 0.2mum for K(+)-stimulated ATPase, 0.1mum for (Na(+),K(+))-stimulated ATPase and 0.003mum for Na(+)-stimulated ATPase activity. 4. The ouabain-sensitive ATPase activities were inactivated by N-ethylmaleimide but the insensitive ATPase activity was not. 5. The three ouabain-sensitive ATPase activities were inhibited about 50% by 1mm-Ca(2+), whereas the ouabain-sensitive Mg(2+)-stimulated ATPase activity was activated by the same concentration of Ca(2+). The preparation was treated with ultrasonics at 20kcyc./sec. The 2min. ultrasonic treatment inactivated the ATPase activities by 50%. 7. The temperature coefficient Q(10) was 6.6 for K(+)-stimulated ATPase activity, 3.7 for (Na(+),K(+))-stimulated ATPase and 2.6 for Na(+)-stimulated ATPase. 8. Organic solvents inactivated the ATPase activities, to which treatment the K(+)-stimulated ATPase was the most resistant. 9. The phosphorylation of the enzyme preparation became less dependent on Na(+) with decreasing pH. This Na(+)-independent phosphorylation at low pH was sensitive to K(+) and hydroxylamine as well as the Na(+)-dependent phosphorylation at neutral pH.
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PMID:Comparison of some minor activities accompanying a preparation of sodium-plus-potassium ion-stimulated adenosine triphosphatase from pig brain. 423 88

The influence of mitochondrial inhibitors, including oligomycin, antimycin and rotenone, on the iodide and oxygen uptake and the nucleotide content of incubated sheep thyroid slices was investigated. Each inhibitor strongly suppressed both iodide and oxygen uptake, and decreased the nucleoside triphosphate content of the slices. In most cases the addition of glucose or mitochondrial substrates restored iodide uptake in inhibitor-treated slices. Inhibitor concentrations sufficient to inhibit iodide uptake strongly had only slight effects on the thyroidal Na(+)+K(+)-activated adenosine triphosphatase. It is concluded that the inhibitors produce their effects by the inhibition in vivo of mitochondrial oxidative phosphorylation. ATP synthesis appears to be essential for iodide uptake to occur, and the high-energy intermediates (or energized state) of oxidative phosphorylation cannot be used to energize the uptake process. To a limited extent glycolytic ATP synthesis can support iodide uptake, which is therefore not exclusively dependent on aerobic metabolism. The mechanism of energy-linked iodide uptake is discussed.
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PMID:Influence of mitochondrial inhibitors on the respiration and energy-dependent uptake of iodide by thyroid slices. 423 89

1. Adenosine triphosphatase activities of dispersions prepared from bovine cerebral cortex that had been frozen, were greater than those of dispersions prepared from fresh tissue. The subcellular distribution of components of the dispersion was not altered by freezing the tissue and a microsomal fraction enriched in Na(+)+K(+)-stimulated adenosine triphosphatase activity was prepared. 2. The bovine cerebral microsomes were further treated with a 2m-sodium iodide reagent to obtain a particulate preparation with minimal Na(+)+K(+)-independent adenosine triphosphatase activity. Na(+)+K(+)-stimulated activity was increased by the sodium iodide treatment and this preparation was shown to be enriched in lipid constituents. 3. Density-gradient centrifugation of the sodium iodide treated preparation gave three main subfractions each containing approximately equal amounts of phospholipid and protein. Further exposure of the sodium iodide-treated preparation to the 2m-sodium iodide reagent altered the distribution of protein and phospholipid among the fractions obtained by density-gradient centrifugation. Dissociation of phospholipids from protein in the sodium iodide-treated preparation was brought about also by high concentrations of arginine. Concentrated solutions of arginine and sodium thiocyanate brought about dissociation of phospholipids from protein of the microsomal preparation. 4. Many amino acids were found to inhibit Na(+)+K(+)-stimulated adenosine triphosphatase activity when present in high concentrations. The inhibition was complex but resulted, in part at least, from diminished affinity for ATP and Na(+) in the presence of the amino acids. 5. A non-ionic detergent, Lubrol W, solubilized up to 40% of the enzyme activity of the sodium iodide-treated preparation together with 30% of the protein and phospholipid in the preparation. Protein was released from the sodium iodide-treated preparation by pancreatic elastase but Na(+)+K(+)-stimulated adenosine triphosphatase activity of the residue was diminished. Ultrasonic treatment of the sodium iodide-treated preparation failed to release a significant proportion of Na(+)+K(+)-stimulated adenosine triphosphatase activity into a form not deposited by ultracentrifugation.
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PMID:The cerebral sodium-plus-potassium ion-stimulated adenosine triphosphatase of bovine brain and its microsomal matrix. 425 Aug 46

1. A particulate Na(+)+K(+)-stimulated adenosine triphosphatase preparation obtained by treatment of bovine cerebral microsomes with a sodium iodide reagent has been further treated with acid anhydrides likely to convert amino groups into acidic derivatives. 2. The extent of acylation of amino groups was determined by reaction of the remaining amino groups with 2,4,6-trinitrobenzenesulphonic acid. The unmodified preparation contains about 1.2 muequiv. of amino groups/mg of protein of which only about 0.5 muequiv. are accounted for by protein amino groups. Kinetics of the trinitrobenzenesulphonic acid reaction with the unmodified preparation are complex and are altered by ATP or ouabain. 3. The compounds examined cause loss of Na(+)+K(+)-stimulated adenosine triphosphatase activity when relatively few amino groups are modified but ATP was found to afford partial protection against inactivation by methylmaleic anhydride. Na(+)+K(+)-stimulated adenosine triphosphatase activity is partly restored to the dimethylmaleylated preparation by hydrolysis of the dimethylmaleyl-amide bonds but not if more than about 20% of the amino groups have been acylated. 4. Supernatants obtained by high-speed centrifugation of the dimethylmaleylated preparation contained up to 45% of the total protein with less than 10% of the total phospholipid. Methylmaleyl and benzenetricarboxylyl derivatives of the enzyme preparation behaved similarly but tetrafluorosuccinylated material was almost entirely deposited by centrifugation.
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PMID:Chemical modification of a cerebral sodium-plus-potassium ion-stimulated adenosine triphosphatase preparation. 425 Aug 47

1. The hypoglycaemic compound diphenyleneiodonium causes rapid and extensive swelling of rat liver mitochondria suspended in 150mm-NH(4)Cl, and in 150mm-KCl in the presence of 2,4-dinitrophenol and valinomycin. This indicates that diphenyleneiodonium catalyses a compulsory exchange of OH(-) for Cl(-) across the mitochondrial inner membrane. Br(-) and SCN(-) were the only other anions found whose exchange for OH(-) is catalysed by diphenyleneiodonium. 2. Diphenyleneiodonium inhibited state 3 respiration of mitochondria and slightly stimulated state 4 respiration with succinate or glutamate as substrate in a standard Cl(-)-containing medium. 3. Diphenyleneiodonium did not inhibit state 3 respiration significantly in two Cl(-)-free media (based on glycerol 2-phosphate or sucrose) but caused some stimulation of state 4. 4. In Cl(-)-containing medium diphenyleneiodonium only slightly inhibited the 2,4-dinitrophenol-stimulated adenosine triphosphatase and it had little effect in the absence of Cl(-). 5. The inhibition of respiration in the presence of Cl(-) is dependent on the Cl(-)-OH(-) exchange. 2,4-Dichlorodiphenyleneiodonium is ten times as active as diphenyleneiodonium both in causing swelling of mitochondria suspended in 150mm-NH(4)Cl and in inhibiting state 3 respiration in Cl(-)-containing medium. Indirect evidence suggests that the Cl(-)-OH(-) exchange impairs the rate of uptake of substrate anions. 6. It is proposed that stimulation of state 4 respiration in the absence of Cl(-) depends, at least in part, on an electrogenic uptake of diphenyleneiodonium cations. 7. Tripropyl-lead acetate, methylmercuric iodide and nine substituted diphenyleneiodonium derivatives also catalyse Cl(-)-OH(-) exchange across the mitochondrial membrane. 8. Diphenyleneiodonium is compared with the trialkyltin compounds, which are also known to mediate Cl(-)-OH(-) exchange and which have in addition strong oligomycin-like effects on respiration. It is concluded that diphenyleneiodonium is specific for catalysing anion-OH(-) exchange and will be a useful reagent for investigating membrane-dependent systems.
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PMID:Biochemical effects of the hypoglycaemic compound diphenyleneiodonnium. Catalysis of anion-hydroxyl ion exchange across the inner membrane of rat liver mitochondria and effects on oxygen uptake. 426 24

Myosin has been purified free of actin from Physarum actomyosin by a two step adaptation of the classical potassium iodide method for depolymerizing actin. On 12% sodium dodecyl sulfate (SDS) gels, the single major slowly moving protein band present in the calcium activated adenosine triphosphatase peak (90% pure) is associated with two fast moving bands of molecular weights of approximately 17,000 and 21,000 daltons, respectively. Densitometry shows the molar ratio of heavy chains to the 21,000 and 17,000 dalton chains on the gels to be 1:2:1. The highly purified myosin forms filaments up to 2.5 microm long in the presence of 5 mM magnesium and 0.05 M KCl. Calcium ions were not required for the formation of long filaments from this highly purified myosin. At low ionic strength (0.05 M KCl) the magnesium ATPase of the highly purified myosin is activated four- to tenfold by muscle actin. The extent of activation is a function of the actin concentration and levels off at high levels of actin. In 0.1 mM calcium salts the ATPase activity is approximately 60% of that in 1 mM EGTA. In summary, Physarum myosin is similar to a number of muscle myosins as well as to platelet and fibroblast myosin, which all possess light chains of two different molecular weights associated with the heavy chains. Under ionic conditions close to those in vivo, highly purified Physarum myosin aggregates into long filaments.
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PMID:Properties of Physarum myosin purified by a potassium iodide procedure. 427 79

Treatment of an isoenzyme of potato apyrase of high adenosine triphosphatase/adenosine diphosphatase (ATPase/ADPase) ratio with iodine, N-acetylimidazole or tetranitromethane inactivates the ATPase activity of this enzyme faster than its ADPase activity. There was protection by substrates with the two last-named substances. This and the appearance of nitrotyrosine suggests the participation of tyrosyl residues in both enzymic activities of potato apyrase. The participation of thiol groups is excluded by the insensitivity of apyrase to p-chloromercuribenzoate. Also, 2-hydroxy-5-nitrobenzyl bromide or carboxymethylation produce the same rate of inactivation of ATPase and ADPase activities. Substrates protect both activities from inactivation. Hydrogen peroxide and photo-oxidation inactivate ATPase activity faster than ADPase activity. There is no protection by substrates. Analysis of pH effects on V(max.) and K(m) suggest different pK values for the amino acid residues at the ATP and ADP sites.
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PMID:Effects of protein-modifying reagents on an isoenzyme of potato apyrase. 435 57

Thyroid status was altered by use of a low-iodine-perchlorate (PC) regimen and either reversal with NaI or injections of L-3,5,3'-triiodothyronine (T3). The PC regimen decreased renal and hepatic oxygen consumption (QO2), alpha-glycerophosphate dehydrogenase (alpha-GPDH), and Na+-K+-dependent adenosine triphosphatase (Na-K-ATPase) to comparable extents (25 vs. 23%, 26 vs. 39%, and 41 vs. 51%, respectively). Administration of T3 to hypothyroid rats elicited dose-dependent increases in hepatic and renal cortical QO2, ouabain-sensitive oxygen consumption (QO2(t)), alpha-GPDH, and Na-K-ATPase activities. The half-maximal increases in all of the response parameters in both kidney and liver were obtained at dosages of 6-32 micrograms T3/100 g body wt. The equivalences in the renal cortical vs. hepatic responses were indicated by correlation coefficients of approximately 0.97. Kidney and liver nuclei also showed similar high-affinity binding of 125I-T3-K1/2 = 29 vs. 18 micrograms T3/100 g body wt, and Nmax = 1.8 vs. 2.1 ng T3/mg DNA. The patterns of the responses plotted as a function of T3 occupancy of the high-affinity nuclear binding sites were indistinguishable in kidney and liver. These results imply similar modes of action of T3, probably initiated at the nuclear level, in both kidney and liver.
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PMID:Nuclear binding of T3 and effects of QO2, Na-K-ATPase, and alpha-GPDH in liver and kidney. 625 44


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