Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.6.1.3 (ATPase)
 65,361 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

1. ATPase isolated from Rhodospirillum rubrum by chloroform extraction and purified by gel filtration or affinity chromatography shows three bands (alpha, beta and gamma) upon electrophoresis in sodium dodecyl sulphate. 2. Ca2+-ATPase activity of the preparation is inhibited by aurovertin and efrapeptin but not by oligomycin. Activity may be inhibited by treatment with 4-chloro-7-nitrobenzofurazan and subsequently restored by dithiothreitol. 3. The enzyme fails to reconstitute photophosphorylation in chromatophores depleted of ATPase by sonic irradiation. 4. Most of the active protein from the crude chloroform extract binds to an affinity chromatography column bearing an immobilised ADP analogue but not to a column bearing immobilised pyrophosphate. 5. In the absence of divalent cations, a component with a very high specific activity for Ca2+-ATPase is eluted from the column by 1.6 mM ATP. This protein migrates asa single band on 5% polyacrylamide gel electrophoresis and only possesses three subunits. At 12 mM ATP an inactive protein is eluted which does not run on acid or alkali polyacrylamide gels and shows a complex subunit structure. 6. ATPase preparations prepared by acetone extraction or by sonic irradiation of chromatophores may also be purified 10-fold by affinity chromatography. 7. The inclusion of 5 mM MgCl2 or CaCl2 during affinity chromatography of chloroform ATPase increases the capacity of the column for the enzyme and demands a higher eluting concentration of ATP. 8. When the enzyme is more than 90% inhibited by efrapeptin or 4-chloro-7-nitrobenzofurazan, the binding characteristics of the enzyme are not affected. 9. 10 mM Na2SO3, which greatly stimulates the Ca2+- and Mg2+-dependent ATPase activity of the enzyme and increases Ki (ADP) for Ca2+-ATPase from 50 to 850 micron, prevents binding to the affinity column. Binding may be restored by the addition of divalent cations. 10. Na2SO3 increases the rate of ATP hydrolysis, ATP-driven H+ translocation and ATP-driven transhydrogenase in chromatophores. 11. It is proposed that anions such as sulphite convert the chromatophore ATPase into a form which is a more efficient energy transducer.
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PMID:Affinity chromatography of H+-translocating adenosine triphosphatase isolated by chloroform extraction of Rhodospirillum rubrum chromatophores. Modification of binding affinity by divalent cations and activating anions. 2 12

H+-Translocating ATPase, which catalyzes ATP synthesis in biomembranes, is composed of a head piece (F1) and a membrane moiety (F0). Using highly-purified F0 from a thermophilic bacterium PS3 (TF0), the following results were obtained. 1. Inhibition by N,N'-dicyclohexylcarbodiimide (DCCD) of H+ conduction through TF0 followed pseudo-first-order kinetics. The second-order rate constant for inhibitor-enzyme interaction was 5 times 10(3) M(-1)-min(-1). 2. H+ conductivity blocked by DCCD was proportional to the amount of DCCD incorporated in the band 8 protein of TF0. When only one-third of the band 8 protein was labeled with DCCD, TF0 hardly transported any H+. 3. By extracting TF0 with chloroform-methanol, the band 8 protein was obtained as a proteolipid. Polyacrylamide gel electrophoresis with dodecyl sulfate and urea showed that the molecular weight was about 6,000. 4. The amino acid composition of band 8 protein indicated that this protein contained an extremely high percentage of hydrophobic amino acids (0.29 in polarity) and was devoid of histidine, tryptophan, cysteine, and lysine. Its minimum molecular weight was 6,500. 5. The role of band 8 protein (DCCD-binding protein) in H+ conduction through TF0 is discussed on the basis of these results.
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PMID:Carbodiimide-binding protein of H+-translocating ATPase and inhibition of H+ conduction by dicyclohexylcarbodiimide. 3 78

Membranes of Escherichia coli contain an adenosine 5'-triphosphate (ATP) energy-transducing system that is inhibited by treatment with dicyclohexylcarbodiimide (DCCD). The carbodiimide-reactive protein component of this system has been identified after treatment with [14C]DCCD. This protein has an apparent molecular weight of 9,000 as judged from acrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and is extracted from the membrane with chloroform-methanol (2:1). These properties are similar to the analogous protein previously identified in mitochondria (Cattell et al., 1971). A mutant strain, RF-7, has been isolated which derives energy from oxidative phosphorylation in the presence of 5 mM DCCD. The ATP hydrolase activity of the membraned system in the mutant was considerably less sensitive to inhibition by DCCD than that in the wild type. The carbodiimide-reactive protein, which was easily labeled by [14C]DCCD in the wild type, was labeled much less rapidly in the carbodiimide-resistant mutant. It is thus concluded that the reaction of DCCD with this specific protein leads to inhibition of the ATP energy-transducing reactions. The mutation causing carbodiimide resistance in strain RF-7 was mapped. It is cotransduced with the uncA gene at a frequency exceeding 90%. The mutationally altered protein causing the carbodiimide resistance was not conclusively identified. However, reconstitution experiments indicate that the altered protein is not one of the subunits of the soluble ATP hydrolase activity, which can be removed from the membrane by washing with 1 mM tris(hydroxymethyl)aminomethane buffer lacking Mg2+. The carbodiimide-reactive protein remains with the membrane residue after removal of the soluble ATP hydrolase and is thus distinct from these subunits as well.
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PMID:Identification of the dicyclohexylcarbodiimide-reactive protein component of the adenosine 5'-triphosphate energy-transducing system of Escherichia coli. 12 94

1. Proteolipid was extracted from the electric organ of Narke japonica by using chloroform/methanol (2:1, v/v). This extract was separated into acetylcholine-binding and non-binding substances by column chromatography. However, acetylcholine-binding substances did not show the characteristic properties of protein. 2. The membrane fragments of the electric organ were separated into three main parts by sucrose density gradient centrifugation. From the heaviest, the fractions were acetylcholine receptor rich, ATPase rich, and acetylcholinesterase rich. 3. The membrane fraction having acetylcholine receptor showed the excitability, the increase of Na+ permeability by the application of cholinergic agonists. However, the acetylcholine binding substance extracted by the organic solvent was richer in the lighter fraction. This substance differed from the true acetylcholine receptor.
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PMID:Acetylcholine-binding substance extracted by using organic solvent and acetylcholine receptor of electric organ of Narke japonica. 12 23

An almost pure form of the bovine heart mitochondrial adenosine triphosphatase (ATPase) is released from the membrane by shaking submitochondrial particles with chloroform. Analyses on polyacrylamide gels and by electron microscopy, and also sensitivity to inhibitors, show that the chloroform-released enzyme is similar to other ATPase preparations from bovine heart mitochondria.
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PMID:A simple and rapid method for the preparation of adenosine triphosphatase from submitochondrial particles. 12 53

1. A procedure for the purification of ATPase extracted by chloroform from baker's yeast (Saccharomyces cerevisiae) is reported. The yield based on submitochondrial particles was 55% and the purification was 100-fold. The isolated complex was homogenous as assessed by gel filtration, ion-exchange chromatography, sedimentation in sucrose gradient and in the analytical ultracentrifuge. The molecular weight determined by gel filtration was 400000 +/- 20000. Ultracentrifugation yielded s020,w = 12.50 +/- 0.13 S and the laser light scattering study gave a diffusion coeficient of D20w - 2.92 X 10(-7) cm2 s-1. The amino acid composition as well as absorption, fluorescence, and circular dichroism spectra, from which the helicity of 39% was evaluated, are given. 2. On polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate, six components with molecular weights of 58500(alpha), 55000 (beta), 42000, 34000 (gamma), 10000(delta), and 8600 (epsilon) were observed with a stoichiometry of 3:3:1:1:1:1. The amino acid composition is given for alpha + beta and gamma as well as delta and epsilon components. 3. The maximum specific activity of the enzyme was 200 U/mg under the optimum conditions. The enzyme was inactivated by incubation at 0 degrees C and strongly inhibited by the antibiotic Dio-9 but not by oligomycin and N, N'-dicyclohexyl-carbodiimide. The effects of kinetic parameters and anions on the enzyme are reported. Two active sites for Mg-ATP with Km values of 0.045mM and 0.37mM and a single activie site for Mg-ITP with Km = 0.179mM were found. A study of the temperature dependence of the maximum activity revealed a straight line in the Arrhenius plots with an activation energy of 11.0 kcal/mol (= 46 kH/mol).
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PMID:Mitochondrial adenosine triphosphatase from yeast, Saccharomyces cerevisiae. Purification, subunit structure and kinetics. 13 2

Highly purified mitochondrial chloroform-released beef heart ATPase had molecular weight 330 000, five bands (alpha, beta, gamma, delta, epsilon) in sodium dodecyl sulfate gel electrophoresis and could restore the oxidative-phosphorylation function of A particles. Maximal inhibition (90%) of the enzyme by N,N'-dicyclohexylcarbodiimide was achieved at a molar ratio of inhibitor to protein of 30 : 1. Chloroform introduced into an aqueous solution of beef heart coupling factor I protected it from cold inactivation.
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PMID:Evidence supporting the identity of beef heart mitochondrial chloroform-released adenosine triphosphatase (ATPase) with coupling factor I. 13 18

A proteolipid isolated from yeast mitochondrial adenosinetriphosphatase (subunit 9) (ATP phosphohydrolase; EC 3.6.1.3) by chloroform/methanol extraction has been shown to discharge photo-induced potentials across a planar phospholipid membrane containing bacteriorhodopsin. Oligomycin, a specific inhibitor of oxidative phosphorylation which binds to this protein, allows the potential gradient to be reestablished. When proteolipid was isolated from an oligomycin-resistant strain, ionophoric activity was still obtained but the effect was not reversed by oligomycin. These studies suggest that the hydrophobic subunit-9 polypeptide is the ionophoric component linking ATP synthesis (hydrolysis) with proton translocation.
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PMID:Oligomycin-dependent ionophoric protein subunit of mitochondrial adenosinetriphosphatase. 14 16

The effects of two protease inhibitors on the solubilization of the membrane-bound Mg2+-adenosine triphosphatase (Mg-ATPase) of Escherichia coli were investigated. p-Aminobenzamidine prevented the solubilization of the Mg-ATPase during treatment of membranes with low-ionic-strength buffers containing ethylenediaminetetraacetic acid. p-Aminobenzamidine did not prevent subsequent solubilization of the Mg-ATPase by treatment of the membranes with chloroform. This method of solubilization yielded a preparation of similar apparent molecular weight but with a 10-fold-increased specific activity as compared with the Mg-ATPase solubilized by washing with low-ionic-strength buffer. However, in contrast to the latter preparation, the chloroform-solubilized Mg-ATPase did not reconstitute ATP-dependent energization of stripped membranes, which were prepared by low-ionic-strength washing in the absence of p-aminobenzamidine. Another protease inhibitor, epsilon-amino-n-caproic acid, did not effect the solubilization of the Mg-ATPase, but did inhibit the loss of activity occurring during concentration, by ultrafiltration, of the Mg-ATPase solublized by the low-ionic-strength treatment.
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PMID:Inhibition, by a protease inhibitor, of the solubilization of the F1-portion of the Mg2+-stimulated adenosine triphosphatase of Escherichia coli. 14 33

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.
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PMID:Dibutylchloromethyltin chloride, a covalent inhibitor of the adenosine triphosphate synthase complex. 14 60


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