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)

Beef heart mitochondrial ATPase (F1) contained 2 mol of ADP and 1 mol of ATP/mol of enzyme, which resisted removal by Sephadex chromatography with dilute buffers or repeated precipitation with ammonium sulfate. The native enzyme also contained two apparently equivalent binding sites, which participated in readily reversible binding of adenyl-5'-ylimidodiphosphate (AMP-P(NH)P), with a Kd of 1.3 mum. The failure of AMP-P(NH)P to compete effectively with ADP for binding sites on F1 may be related to the failure of the analog to inhibit oxidative phosphorylation. Virtually complete removal of all adenine nucleotides from F1 occurred when the enzyme was chromatographed on columns of Sephadex equilibrated with 50% glycerol. No loss in ATPase activity was observed following removal of nucleotides from the enzyme, which was then capable of binding more than 4 mol of ADP and almost 5 mol of AMP-P(NH)P/mol of protein. Subsequent chromatography on columns of Sephadex equilibrated with dilute buffers containing Mg2+ removed only 1.5 mol of ADP and no AMP-P(NH)P from the enzyme. Reconstitution of F1 with ADP or with almost 5 mol of AMP-P(NH)P resulted in preparations that exhibited an undiminished capacity to restore oxidative phosphorylation in F1-deficient submitochondrial particles.
J Biol Chem 1975 Sep 10
PMID:Interaction of adenine nucleotides with multiple binding sites on beef heart mitochondrial adenosine triphosphatase. 12 56

1. A formula is given that describes the appearance of [14C]ATPADP outside the mitochondria after the addition of [14C] 1atp during the steady-state uncoupler-induced hydrolysis of extramitochondrial ATP. If the transported adenine nucleotides equilibrate with the intramitochondrial pool, [14C]ADP0 would be expected to appear with a lag phase that corresponds with the time needed for the radioactive labelling of the intramitochondrial adenine nucleotide pool. 2. The rates of formation of [14C]ADP outside the mitochondria after addition of [14C]ATP during the steady-state uncoupler-induced ATP hydrolysis catalysed by rat-liver mitochondria at 0 degree C were measured. 3. In the presence of carbonyl cyanide m-chlorophenylhydrazone the time course of the [14]ADPo formation was the same as that predicted on the basis of the above assumption. 4. In the presence of the less effective uncoupler, 2,4-dinitrophenol, the time course of [14C]ADPo formation was not consistent with the theoretical predictions: no lag phase was present and the measured rate was higher than the maximal calculated rate. These results can be explained by assuming a functional interaction between the adenine nucleotide translocator and the mitochondrial ATPase (F1). 5. It is concluded that under phosphorylating as well as dephosphorylating conditions, the adenine nucleotide translocator and the mitochondrial ATPase can be functionally linked to catalyse phosphorylation or dephosphorylation of extramitochondrial ADP or ATP, without participation of the intramitochondrial adenine nucleotides.
Biochim Biophys Acta 1976 Sep 13
PMID:Role of the intramitochondrial adenine nucleotides as intermediates in the uncoupler-induced hydrolysis of extramitochondrial ATP. 13 45

2,4,3',5'-tetrahydroxystilbene (THS) wa s found to inhibit rat liver mitochondrial adenosine triphosphatase (ATPase) activity induced by various concentrations of 2,4-dinitrophenol (DNP). The I50 was found to be 17 nmoles/mg mitochondrial protein. The maximum inhibitory effects of oligomycin and atractyloside on the DNP-activated mitochondrial ATPase activity can be enhanced by adding THS. The atractyloside-insensitive ATPase activity of Lubrol-treated rat liver mitochondria was also inhibited by low concentration of THS. The tetramethoxyderivative of THS was much less effective than the parent compound in depressing the ATPase activity of both intact and Lubrol-treated mitochondria. These observations suggest that the phenolic groups are essential for the mitochondrial actions of THS, and this compound most probably acts by a mechanism different from oligomycin on the mitochondrial ATPase complex.
Chem Biol Interact 1977 Sep
PMID:Inhibition of mitochondrial ATPase by 2,4,3',5'-tetrahydroxystilbene. 14 31

1. The fatty acid composition of the ole-1 and ole-1 petite mutants of Saccharomyces cerevisiae was manipulated by growing the organism in the presence of defined supplements of Tween 80 or by allowing cells that had first been grown in the presence of Tween 80 to deplete their unsaturated fatty acids by sequent growth in the absence of Tween 80. 2. The transition temperature of Arrhenius plots of mitochondrial ATPase (adenosine triphosphatase) increases as the unsaturated fatty acid content is lowered. 3. Cells require larger amounts of unsaturated fatty acids to grow on ethanol at lower temperatures. 4. Cells that stop growing owing to unsaturated fatty acid depletion at low temperatures are induced to grow further by raising the temperature and this results in a further depletion of unsaturated acids. This is due to a higher rate, but not a greater efficiency, of mitochondrial ATP synthesis. 5. Arrhenius plots of the passive permeability of mitochondria to protons between 4 and 37 degrees C are linear. The rate and the Arrhenius activation energy of proton entry increase greatly as the unsaturated fatty acid content is lowered. 6. Unsaturated fatty acid depletion has the same effects on the proton permeability of ole-1 petite mitochondria, indicating that the mitochondrially synthesized subunits of the ATPase are not involved in the enhanced rates of proton entry. 7. The adenylate energy charge of depleted ole-1 cells is greatly decreased by growth on ethanol medium. 8. The adenylate energy charge of isolated mitochondria is also lowered by unsaturated fatty acid depletion. 9. The results confirm that unsaturated fatty acid depletion uncouples oxidative phosphorylation in yeast both in vivo and in vitro, and is a consequence of changes in the lipid part of the membrane.
Biochem J 1977 Sep 15
PMID:The effects of unsaturated fatty acid depletion on the proton permeability and energetic functions of yeast mitochondria. 14 59

1. The synthesis of dibutylchloromethyltin chloride, a new covalent inhibitor of the mitochondrial ATP synthase [oligomycin-sensitive ATPase (adenosine triphosphatase)] complex is described, together with a method for preparing dibutylchloro[(3)H]methyltin chloride. 2. Studies with the yeast mitochondrial oligomycin-sensitive ATPase complex show that dibutylchloromethyltin chloride inhibits both the membrane-bound enzyme and also the purified Triton X-100-dispersed preparation. 3. F(1)-ATPase is not inhibited even at 500nmol of dibutylchloromethyltin chloride/mg of protein, and the general inhibitory properties are similar to those of triethyltin, oligomycin and dicyclohexylcarbodi-imide, known energy-transfer inhibitors of oxidative phosphorylation. 4. Binding studies with yeast submitochondrial particles show that dibutylchloromethyltin chloride antagonizes the binding of triethyl[(113)Sn]tin, indicating that there is an interaction between the two inhibitor-binding sites. 5. Unlike triethyltin, inhibition by dibutylchloromethyltin chloride is due to a covalent interaction which titrates a component of the inner mitochondrial membrane present at a concentration of 8-9nmol/mg of protein. 6. All of the labelled component can be extracted with chloroform/methanol (2:1, v/v), and sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of the chloroform/methanol extract indicates that the labelled component has an apparent mol.wt. of 6000-8000. However, t.l.c. reveals the presence of only one labelled component which is lipophilic and non-protein and is distinct from the free inhibitor, mitochondrial phospholipids and the dicyclohexylcarbodi-imide-binding protein (subunit 9). 7. Inhibition of mitochondrial ATPase and oxidative phosphorylation is correlated with specific interaction with a non-protein lipophilic component of the mitochondrial inner membrane which is proposed to be a co-factor or intermediate of oxidative phosphorylation.
Biochem J 1977 Sep 15
PMID:Dibutylchloromethyltin chloride, a covalent inhibitor of the adenosine triphosphate synthase complex. 14 60

The mitochondrial F1-ATPase is irreversibly inactivated by the adenine nucleotide analogue, p-fluorosulfonylbenzoyl-5'-adenosine. This inactivation is partly prevented by the presence of bound adenine nucleotides. Inactivations of the ATPase with p-fluorosulfonyl[14C]benzoyl-5'-adenosine were most efficiently accomplished with the nucleotide-free enzyme at pH 7.0, in a buffer containing 20% glycerol. Under these conditions, 4.2 g atoms of 14C are incorporated per 350,000 g of enzyme when the ATPase is inactivated by 90% by its reaction with 2 mM p-fluorosulfonyl[14C]benzoyl-5'-adenosine. Isolation of the component polypeptide chains of the labeled ATPase showed that all of the radioactivity was associated with the two largest subunits. The isolated alpha subunit contained 0.45 g atom of 14C/mol and the isolated beta subunit contained 0.88 g atom of 14C/mol. Hence, the inactivation can be correlated with the incorporation of 14C into the beta subunit. This suggests that the hydrolytic site of the enzyme resides on this subunit. The majority of the radioactivity in a tryptic digest of labeled beta subunit is contained ina tryptic peptide that has the following amino acid sequence: Ile-Met-Asp-Pro-Asn-Ile-Val-Gly-Ser-Glu-His-Tyr-Asp-Val-Ala-Arg, where Tyr is the radioactive derivative of the tyrosine residue that was sulfonylated during the inactivation.
J Biol Chem 1978 Sep 10
PMID:Identification of a tyrosine residue at a nucleotide binding site in the beta subunit of the mitochondrial ATPase with p-fluorosulfonyl[14C]-benzoyl-5'-adenosine. 15 Apr 16

1. The oxidation of linoleate by rat-liver mitochondria has been studied as a function of substrate concentration. The oxidation of other long-chain unsaturated fatty acids shows similar characteristics. 2. At low concentrations, linoleate is readily oxidized in the absence of carnitine. Its rate of activation by the intramitochondrial acyl-CoA synthetase (EC 6.2.1.2) and subsequent oxidation is limited by the availability of intra-mitochondrial ATP. 3. A gradual increase of the linoleate concentration leads to (i) a strong depression of the rate of linoleate oxidation, and (ii) uncoupling of respiratory-chain phosphorylation together with induction of a mitochondrial ATPase activity. At still higher linoleate concentrations this ATPase activity is lowered rather than further stimulated and, concomitantly, the rate of linoleate oxidation increases again. 4. Evidence is presented that the inhibition by linoleate of the ATPase activity occurs at the level of the ATPase complex itself. This oligomycin-like effect of linoleate allows intramitochondrial linoleate activation to take place at the expense of ATP derived from substrate-level phosphorylation. 5. At very high concentrations of linoleate, its detergent action predominates and causes a complete inhibition of respiration as well as an extensive stimulation of an oligomycin-insensitive, Mg2+-dependent ATPase activity. 6. Measurement of the binding of radioactively labelled linoleate by isolated mitochondria shows that, at a given ratio of linoleate to mitochondrial protein, the ratio of bound to added linoleate is dependent on the concentration of the mitochondria.
Biochim Biophys Acta 1978 Sep 07
PMID:The oxidation of long-chain unsaturated fatty acids by isolated rat liver mitochondria as a function of substrate concentration. 15 Aug 57

A comparative study has been made of the effects of a variety of inhibitors on the plasma membrane ATPase and mitochondrial ATPase of Neurospora crassa. The most specific inhibitors proved to be vanadate and diethylstilbestrol for the plasma membrane ATPase and azide, oligomycin, venturicidin, and leucinostatin for mitochondrial ATPase. N,N'-Dicyclohexylcarbodiimide, octylguanidine, triphenylsulfonium chloride, and quercetin and related bioflavonoids inhibited both enzymes, although with different concentration dependences. Other compounds that were tested (phaseolin, fusicoccin, deoxycorticosterone, alachlor, salicyclic acid, N-1-napthylphthalamate, triiodobenzoic acid, cyclic AMP, cyclic GMP, theobromine, theophylline, and histamine) had no significant effect on either enzyme. Overall, the results indicate that the plasma membrane and mitochondrial ATPases are distinct enzymes, in spite of the fact that they may play related roles in H+ transport across their respective membranes.
Biochim Biophys Acta 1978 Sep 11
PMID:Effects of inhibitors on the plasma membrane and mitochondrial adenosine triphosphatases of Neurospora crassa. 15 57

Anti-inflammatory mechanism of 2-(2-fluoro-4-biphenylyl) propionic acid (Flurbiprofen, FP-70) was studied by various analysis in comparison with other drugs. It was found in the test of rat edema induced by various phlogists that carrageenin and yeast-induced edemas were markedly inhibited by FP-70, whereas dextran, formalin, serotonin and bradykinin-induced edemas were scarcely inhibited by FP-70. The action of FP-70 was similar to that of soy bean trypsin inhibitor. However, FP-70 showed no effects on kinin synthetase and kininase. FP-70 showed a marked inhibition on prostaglandin synthesis. The inhibitory effect of FP-70 was 10.1, 96.5 and 2280.6 times as large as indomethacin, ibuprofen and acetylsalicylic acid, respectively. FP-70 did not inhibit the permeability of dye induced by prostaglandin E2 in the rat skin. FP-70 inhibited the acid phosphatase and beta-glucuronidase activities of isolated lysosome of rat liver and also suppressed the release of acid phosphatase from the lysosome. These effects were similar to those of indomethacin. On the other hand, FP-70 suppressed markedly the heat-induced hemolysis of dog erythrocytes. The effect was similar to that of indomethacin and was 10 times stronger than those of ibuprofen, ibufenac and phenylbutazone. Activation of rat liver mitochondrial ATPase by FP-70 at a concentration of 10 muM was 74.7%, while indomethacin showed 37.8% activation at the same concentration. FP-70 as well as ibuprofen and phenylbutazone uncoupled the oxidative phosphorylation in rat liver mitochondria. From the above and previously reported results, it is suggested that the potent anti-inflammatory action of FP-70 is the result of the following effects; inhibition on the protein and leucocyte migration, inhibition on the prostaglandin synthesis, stabilization of the cell membrane and activation of ATPase.
Nihon Yakurigaku Zasshi 1976 Sep
PMID:[Mechanism of anti-inflammatory action of 2-(2-fluoro-4-biphenylyl) propionic acid (flurbiprofen)]. 18 38

Earlier work has shown that mitochondrial proteins synthesized in the cytosol are initially made as larger precursors which are then transferred into the organelles and processed to their mature size in the absence of protein synthesis. It is now demonstrated that depletion of the mitochondrial matrix ATP in intact yeast spheroplasts by various combinations of inhibitors and mutations prevents the processing of precursors to the three largest subunits of the mitochondrial F1-ATPase and two subunits of the cytochrome bc1 complex. These polypeptides are all synthesized outside the mitochondria and transported to the mitochondrial matrix or inserted into the mitochondrial inner membrane. In contrast, depletion of the matrix ATP does not inhibit processing of the precursor to cytochrome c peroxidase; this enzyme is located in the mitochondrial intermembrane space which is freely accessible to ATP made in the cytosol. The processing of extramitochondrially made precursors or the transfer of these precursors across the mitochondrial inner membrane is thus dependent on ATP.
Proc Natl Acad Sci U S A 1979 Sep
PMID:Energy-dependent processing of cytoplasmically made precursors to mitochondrial proteins. 38 40


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