Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:3.6.3.14 (ATP synthase)
7,042 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effects of sodium salicylate (SS), phenazone (Ph) and aminophenazone (APh) on mitochondrial respiration respiration and oxidative phosphorylation were studied in vitro, SS inhibited state 3 but stimulated state 4 of respiration, if alpha-ketoglutarate and succinate were used as the substrates. The inhibition of state 3 of respiration was not reversed by 2,4-dinitrophenol (DNP). Ph and APh inhibited the respiratory state 3 without affecting the state 4 in the presence of the same substrates, and the produced inhibition in state 3 was reversible by DNP. Studies on ATP synthesis have revealed that SS was the only antypyretic tested that exerted an uncoupling action. SS stimulated the mitochondrial ATPase activity but inhibited it after uncoupling of oxidative phosphorylation with DNP. The mitochondrial ATPase activity remained uninfluenced by Ph or APh. The only similar action of all the drugs investigated was the inhibition of oxidation in the respiratory state 3.
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PMID:The effects of antipyretics on metabolism processes in rat liver mitochondria. Part I. The action of sodium salicylate, and pyrazolones on the reaction of respiratory chain. 0 75

1. The specific activity of mitochondrial ATPase (adenosine triphosphatase) in extracts of Schizosaccharomyces pombe decreased 2.5-fold as the glucose concentration in the growth medium decreased from 50mM to 15mM. 2. During the late exponential phase of growth, ATPase activity doubled. 3. Sensitivity to oligomycin and Dio-9 as measured by values for I50(mug of inhibitor/mg of protein giving 50% inhibition) at pH 6.8 increased sixfold and ninefold respectively during the initial decrease in ATPase activity, and this degree of sensitivity was maintained for the remainder of the growth cycle. 4. Increased sensitivity to NN'-dicyclohexylcarbodi-imide, triethyltin and venturicidin was also observed during the early stage of glucose de-repression. 5. Smaller increases in sensitivity to efrapeptin, aurovertin, 7-chloro-4-nitrobenzo-2-oxa-1,3-diaz-le, quercetin and spegazzinine also occurred. 6. The ATPase of glycerol-grown cells was less sensitive to inhibitors than that of glucose-repressed cells; change in values for I50 were not so marked during the growth cycle of cells growing with glycerol. 7. When submitochondrial particles from glycerol-grown cells were tested by passage through Sephadex G-50, a fourfold increase in activity was accompanied by increased inhibitor resistance. 8. Gel filtration of submitochondrial particles from glucose-de-repressed cells gave similar results, whereas loss of ATPase occurred in submitochondrial particles from glucose-repressed cells. 9. It is proposed that alterations in sensitivity to inhibitors at different stages of glucose derepression may be partly controlled by a naturally occuring inhibitor of ATPase. 10. The inhibitors tested may be classififed into two groups on the basis of alterations of sensitivity of the ATPase during physiological modification: (a) oligomycin, Dio-9, NN'-dicyclohexylcarbodi-imide, venturicidin and triethyltin, and (b) efrapeptin, aurovertin, 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole, quercetin and spegazzinine.
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PMID:Mitochondrial adenosine triphosphatase of the fission yeast, Schizosaccharomyces pombe 972h-. Changes in activity and inhibitor-sensitivity in response to catabolite repression. 1 53

(1) The mitochondrial ATPase (EC 3.6.1.3) Ehrlich ascites cell mitochondria, was inhibited by D-glucose under physiological concentrations of ATP. The generation of ADP by the mitochondrial bound hexokinase, seems to be the reason for the D-glucose inhibitory effect. Reversal of the inhibitory effect of ADP on Ehrlich ascites cell mitochondria ATPase by an ATP-regenerating system was achieved. (2) Dissociation of mitochondrial bound hexokinase from the mitochondria eliminated the inhibitory effect of D-glucose. Rebinding of the hexokinase to the mitochondria regenerated the D-glucose inhibitory effect on Ehrlich ascites cell mitochondria ATPase. (3) Bioflavonoids such as quercetin inhibit the mitochondrial hexokinase activity, but do not change the mitochondrial ATPase activity of isolated Ehrlich ascites tumor cell mitochondria. (4) The inhibitory effect of bioflavonoids on mitochondrial bound hexokinase activity is shown to be dissociable from the ascites tumor cell mitochondria and seems to be associated with regulatory rather than catalitic sites of the enzyme.
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PMID:Bioflavonoid regulation of ATPase and hexokinase activity in Ehrlich ascites cell mitochondria. 1 95

Beef heart mitochondrial ATPase (F1) exhibited a single binding site for Pi. The interaction with Pi was reversible, partially dependent on the presence of divalent metal ions, and characterized by a dissociation constant at pH 7.5 of 80 micronM. A variety of substances known to influence oxidative phosphorylation or the activity of the soluble ATPase (F1) also influenced Pi binding by the enzyme. Thus aurovertin, an inhibitor of oxidative phosphorylation, which was bound tightly by F1 and inhibited ATPase activity, enhanced Pi binding via a 4-fold increase in the affinity of the enzyme for Pi (KD = 20 micronM) but did not alter binding stoichiometry. Anions such as SO4(2-), SO3(2-), chromate, and 2,4-dinitrophenolate, which stimulated ATPase activity of F1, also enhanced Pi binding. Inhibitors of ATPase activity such as nickel/bathophenanthroline and the protein ATPase inhibitor of Pullman and Monroy (Pullman, M. E., and Monroy, G. C. (1963) J. Biol. Chem. 238, 3762-3769) inhibited Pi binding. The adenine nucleotides ADP, ATP, and the ATP analog adenylyl imidodiphosphate as well as the Pi analog arsenate, also inhibited Pi binding. The observations suggest that the Pi binding site was located in or near an adenine nucleotide binding site on the molecule.
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PMID:Reversible binding of Pi by beef heart mitochondrial adenosine triphosphatase. 1 6

We have compared the adenosine triphosphatase (ATPase) activity of mitochondria prepared from wild-type Neurospora crassa and from poky, a maternally inherited mutant known to possess defective mitochondrial ribosomes and reduced amounts of cytochromes aa3 and b. poky contains two distinct forms of mitochondrial ATPase. The first is normal in its Km for ATP, specificity for nucleotides and divalent cations, pH optimum, cold stability, and sensitivity to inhibitors (oligomycin, N,N-dicyclohexyl carbodiimide, and adenylyl imidodiphosphate). The fact that membrane-bound, cold-stable, oligomycin-sensitive ATPase activity is present in poky (with an activity of 1.93 +/- 0.03 mumol/min-mg of protein compared with 1.33 +/- 0.07 mumol/min-mg of protein in the wild-type strain) and also in chloramphenicol-grown wild-type cells suggests that products of mitochondrial protein synthesis play only a limited role in the attachment of the mitochondrial ATPase to the membrane in Neurospora. poky also contains a second form of mitochondrial ATPase, which has an activity of 1.5 +/- 0.2 mumol/min-mg of protein, is oligomycin sensitive but cold labile, and presumably is attached less firmly to the mitochondrial membrane. The two forms, added together, represent a substantial overproduction of mitochondrial ATPase by poky.
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PMID:Mitochondrial adenosine triphosphatase of wild-type and poky Neurospora crassa. 2 38

Mammalian and avian muscles were examined histochemically and biochemically to determine the relative contribution of membrane bound (mitochondrial and sarcotubular) ATPases under the same conditions employed for myofibrillar ATPase. For histochemically investigated Ca+(+)-ATPase activity following incubation at pH 9.4 according to the calcium-citro-phosphate technique, avian muscle displayed distinct mitochondrial localization in both dark and light staining fibres. However, mitochondrial localization did not occur in mammalian muscle fibres. Pretreatment of unfixed frozen sections with ouabain, cyanide and acetone did not prevent the reticular distribution in avian muscle fibres. The present study demonstrates that "myofibrillar" localization is achieved by the Ca+(+)-precipitation technique: provided frozen sections are pretreated with cold acetone, fixed in a fixative containing oligomycin or azide and then incubated in a medium containing glycine-NaO H as buffer. Mitochondria prepared by successive mechanical homogenization or by Nagarse treatment plus 2 min homogenization develop different ATPase activities at pH 9.4 7.4 6.0 and 4.35 as well as stimulation by 70 mM Ca++ at these pHs compared to those ATPase activities in the homogenate of mixed hamster hind leg muscles. Glycerol-3-phosphate dehydrogenase and creatine kinase (both located at the outer surface of the inner mitochondrial membrane) and succinate dehydrogenase and glutamate dehydrogenase (localized at the inner mitochondrial membrane and in the matrix resp.) also show different activities in both mitochondria preparations indicating different membrane properties of both mitochondria. Evidence is obtained that using the calcium-citro-phosphate technique at pH 9.4 oligomycin-sensitive and -insensitive ATPases are activated by Ca++ in both mitochondria preparations. Since in muscle homogenate less than 10% of Ca+(+)-stimulated ATPase activity is oligomycin-sensitive, mitochondrial ATPase exhibit only a small portion of total ATPase from mixed hamster hind leg muscles.
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PMID:Histochemical and biochemical investigations of adenosine triphosphatase in vertebrate mixed muscles. 4 33

5-Hydroxy-1,2-naphthalenedicarboxylic anhydride is closely related to its precursor dibasic acid which is a metabolite of the carcinogenic polynuclear hydrocarbon dibenz[a,h]anthracene. The anhydride inhibited respiration of coupled mitochondria. This inhibition was relieved by 2,4-dinitrophenol. Several mitochondrial volume change processes energized by ATP were also inhibited by the anhydride. Both the mitochondrial ATPase activity induced by 2,4-dinitrophenol and the ATPase activity of submitochondrial particles induced by magnesium ion were inhibited by the anhydride. The spectrum of inhibitory activity was not associated with acetic anhydride, succinic anhydride, or phthalic anhydride. The data indicate that 5-hydroxy-1,2-naphthalenedicarboxylic anhydride inhibits the machinery of oxidative phosphorylation in a manner similar to rutamycin. 5-Hydroxy-1,2-naphthalenedicarboxylic anhydride is the first molecule derived from a carcinogen with such inhibitory properties.
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PMID:A new inhibitor of coupled oxidative phosphorylation, 5-hydroxynaphthalenedicarboxylic anhydride, a derivative of a carcinogenic polynuclear hydrocarbon. 5 70

The soluble beef heart mitochondrial ATPase (F1) contains eight sulfhydryl groups and two disulfide bonds. N-Ethylmaleimide has been used to radioactively label the sulfhydryl groups before and after cleavage of the disulfide bonds by dithiothreitol. After subjecting the labeled protein to polyacrylamide gel electrophoresis in sodium dodecyl sulfate and measuring radioactivity in each of the separated subunits the location of all the sulfhydryl groups and the disulfide bonds may be specified. The conclusions are supported by direct examination of depolymerized, unreduced, enzyme by polyacrylamide gel electrophoresis. The results also indicate that current ideas regarding the overall subunit structure of this enzyme may be incorrect, and this is discussed in light of new data presented here.
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PMID:Mitochondrial adenosine triphosphatase. Location of sulfhydryl groups and disulfide bonds in soluble enzyme from beef heart. 12 57

The lipid-free particulate preparations of the mitochondrial ATPase require phospholipid for activity and can be inhibited by oligomycin, as has been demonstrated previously. In this communication a steady state analysis of the activation of a particulate preparation of the ATPase by phospholipids and its subsequent inhibition by oligomycin has been carried out. The relative affinity of the ATPase for purified phospholipids has been determined by measuring the Km for activation (Ka) for several phospholipids. The Ka values varied from 30 to 100 mum. The Vmax in the presence of phosphatides varies from 0.29 to 1.11 mumol ATP hydrolyzed/min/mg of protein; no correlation is noted between the relative affinity of the enzyme for a phospholipid and the V max value. Higher V max values are noted with the more acidic phospholipids, however. Sodium dodecyl sulfate and monoolein also activate with Ka values of 25 and 800 mum, respectively. Diglycerides, however, do not activate. With all lipids the ATPase activity stimulated is oligomycin-sensitive. The Ki values for oligomycin range from 0.1 to 0.6 mum. Oligomycin is a competitive inhibitor with respect to all the phospholipids tested except phosphatidylethanolamine and phosphatidyglycerol. It is also competitive with respect to sodium dodecyl sulfate (k-i equals 0.94 mum). In reciprocal plots of activity versus ATP concentration, with and without oligomycin, an intercept consistent with either mixed or partial noncompetitive inhibition kinetics is noted. Comparable K-i values for oligomycin are obtained when calculated assuming either mixed or partial noncompetitive inhibition. The Km for ATP is the same in the unactivated and the lipid activated particulate ATPase; the value obtained is slightly lower than the Km for ATP in the solubilized, purified ATPase. Using a spectrophotometric assay the time required for activation with phospholipid and inhibition with oligomycin has also been determined. This investigation suggests the possibility that activation of the ATPase is due a position to interact with the water-soluble substrate. Consistent with the above suggestion is the supposition that the lipids do not necessarily confer inhibitor sensitivity to the ATPase, but rather allow an oligomycin-sensitive activity to be expressed.
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PMID:The relationship between the bovine heart mitochondrial adenosine triphosphatase, lipophilic compounds, and oligomycin. 12 47

1. The bound nucleotides of the beef-heart mitochondrial ATPase (F1) are lost during cold inactivation followed by (NH4)2SO4 precipitation. The release of tightly bound ATP parallels the loss of ATPase activity during this process. 2. During cold inactivation, the sedimentation coefficient (s20, w) of the ATPase first declines from 12.1 S to 9 S, then to 3.5 S. (NH4)2SO4 precipitation of the 9-S component also leads to dissociation into subunits with s20, w of 3.5 S. 3. The 9-S component still contains the bound nucleotides, which are removed when it dissociated into smaller subunits. 4. Reactivation of cold-inactivated ATPase by incubation at 30 degrees C is increased by the presence of 25% glycerol. ATP, however, does not have any clearcut effect on the degree of reactivation in the presence of glycerol. 5. ADP is an inhibitor of the reactivation, probably because it exchanges during reactivation for bound ATP giving rise to an inactive 12-S component. 6. The exchange of tightly bound nucleotides with added adenine nucleotides is more extensive and faster with cold-inactivated ATPase than with the native enzyme. During reactivation up to 1.6 moles of ATP and 1.0 mole ADP can exchange per mole enzyme. 7. Incubation with GTP, CTP or inorganic pyrophosphate induces an increased activity of the ATPase, which, however, soon declines in the presence of ATP. It also disappears on precipitation of GTP-treated enzyme with (NH4)2SO4.
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PMID:Nucleotide-binding properties of native and cold-treated mitochondrial ATPase. 12 64


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