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)

1. Modification of a single amino acid residue by introduction of the nitrobenzofurazan group inactivates mitochondrial ATPase (adenosine triphosphatase) when membrane-bound in submitochondrial particles. The similarity between the reactions of both membrane-bound and isolated ATPase with 4-chloro-7-nitrobenzofurazan indicates that the single essential tryosine residue identified in the isolated enzyme [Ferguson, Loyd, Lyons & Radda (1975) Eur. J. Biochem. 54, 117-126] Is also a feature of the membrane-bound ATPase. 2. A procedure is presented for estimating the ATPase content of the inner mitochondrial membrane. It is based on the specificity of the incorporation of the nitrobenzofurazan group, and the ready removal of this group by compounds that contain a thiol group. This method indicates that 8.5% of the membrane protein is ATPase. The procedure should be applicable to the titration of the energy-transducing ATPases of bacterial plasma membranes and of the thylakoid membranes of chloroplasts. 3. Combination of the data obtained on the ATPase content of the bovine heart inner mitochondrial membrane with a titration of the cytochrome bc1 complex with antimycin indicates that these two components of the membrane are present in approximately equal amounts.
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PMID:A method for determining the adenosine triphosphatase content of energy-transducing membranes. reaction of 4-chloro-7-nitrobenzofurazan with the adenosine triphosphatase of bovine heart submitochondrial particles. 13 62

1. Isolated F1 (mitochondrial ATPase) binds to urea-treated submitochondrial particles suspended in sucrose/Tris/EDTA with a dissociation constant of 0.1 muM. 2. About one-third of the F1 and the oligomycin-sensitivity conferring protein (OSCP) are lost during preparation of submitochondrial particles prepared at high pH (A particles). None is lost from particles treated with trypsin (T particles). 3. After further treatment with alkali of urea-treated particles, binding of F1 requires the addition of OSCP. Maximum binding is reached when both OSCP and Fc2 are added. The concentration of F1-binding sites in the presence of both OSCP and Fc2 is about the same as that in TU particles. 4. After further extraction with silicotungstate of urea- and alkali-treated particles, OSCP no longer induces binding of F1, unless Fc2 is also present. Fc2 induces binding in the absence of OSCP but with a lower binding constant and, in contrast to results under all the other conditions studied in this paper, the ATPase activity is oligomycin insensitive. 5. It is tentatively concluded that OSCP is the binding site for F1 and Fc2 is the binding site for OSCP.
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PMID:Proteins required for the binding of mitrochondrial ATPase to the mitochondrial inner membrane. 13 85

1. The following bifunctional reagents, dimethylsuberimidiate, dimethyladipimidate, methylmercaptobutyrimidate have been used to produce dimers between the neighboring subunits of beef heart F1-ATPase. 2. Treatment of beef heart F1-ATPase with dimethylsuberimidate or dimethyladipimidate resulted in the formation of four cross-linked products. Their molecular weights determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis were 11 500, 105 000, 95 000 and 80 000, respectively. The products of molecular weight 115 000 and 105 000 were predominant and could be detected at the early stage of the cross-linking reaction. Treatment of beef heart F1-ATPase with methylmercaptobutyrimidate resulted in the accumulation of the product of molecular weight 115 000 and in traces of products of lower molecular weight. When the cross-linked products obtained with methylmercaptobutyrimidate were cleaved by beta-mercaptoethanol, the original gel electrophoresis pattern was restored. 3. Cross-linking of beef heart F1-ATPase by dimethylsuberimidate, dimethyladipimidate and methylmercaptobutyrimidate was accompanied by a loss of the ATPase activity. Cleavage of the cross-linked products obtained with methylmercaptobutyrimidate did not restore the original ATPase activity. 4. Identification of subunits A and B in the products of molecular weight 115 000 and 105 000 was achieved by specific labeling of subunit A with N-[14C]ethylmaleimide and of subunit B by chloronitro [14C]benzooxodiazole. Both products were able to bind N-[14C]ethylmaleimide; only the 105 000 dalton product was able to bind chloronitro [14C]benzooxodiazole. 5. The product of molecular weight 115 000 obtained by treatment of beef heart ATPase with methylmercaptobutyrimidate could bind N-[14C]ethylmaleimide. Its cleavage, following N-[14C]ethylmaleimide binding, yielded one labeled peptide identified with subunit A by polyacrylamide gel electrophoresis. 6. The above results indicate that the product of molecular weight 115 000 is a dimer containing two subunits A and that the product of molecular weight 105 000 is a dimer containing one subunit A and one subunit B. It can therefore be concluded that, in beef heart F1-ATPase, the A subunits are close to each other and that subunit A is close to subunit B. In contrast the B sublnits are probably too far from each other to be cross-linked by dimethylsuberimidate, dimethyladipimidate or methylmercaptobutyrimidate.
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PMID:Structure of beef heart mitochondrial F1-ATPase. Arrangement of subunits as disclosed by cross-linking reagents and selective labeling by radioactive ligands. 13 87

A heat-stable protein has been detected in Saccharomyces cerevisiae which inhibits mitochondrial ATPase activity. The protein inhibitor has been isolated from extracts prepared by brief heat treatment of unbroken cell suspensions. The isolated inhibitor is a small basic protein (molecular weight close to 7000, isoelectric proint 9.05) devoid of tryptophan, tyrosine, and cysteine as well as proline. The NHP2-terminal amino acid is serine. The ultraviolet absorption spectrum shows the vibrational fine structure of the phenyl-alanine band. Like the ATPase inhibitor from bovine heart mitochondria the yeast inhibitor is rapidly destroyed by trypsin. It is also inactivated by the yeast proteinases A and B. Radioimmunological analysis indicates that the inhibitor is synthesized on cytoplasmic ribosomes. Its accumulation seems to be connected to the formation of the mitochondrial ATPase complex, since its specific activity is greatly reduced both in extracts obtained from the F1-ATPase-deficient nuclear mutant pet 936 and from the cytoplasmic petite mutant D 273-10B-1.
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PMID:A protein inhibitor of mitochondrial adenosine triphosphatase (F1) from Saccharomyces cerevisiae. 13 3

ATP synthase preparations [complex V, proton-translocatin ATPase (adenosine triphosphatase) and oligomycin-sensitive ATPase ] contain stoicheiometric amounts of lipoic acid residues (up to 6mol of lipoic acid/mol of ATPase complex) and catalyse net ATP synthesis in an uncoupler-and oligomycin-sensitive reaction utilizing dihydrolipoate, oleoyl-CoA and oleic acid, or in a reaction utilizing oleoyl-S-lipoate. The terminal reactions of oxidative phosphorylation are thus analogous to those of substrate-level phosphorylation.
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PMID:Studies of energy-linked reactions. Net synthesis of adenosine triphosphate by isolated adenosine triphosphate synthase preparations: a role for lipoic acid and unsaturated fatty acids. 13 19

1. Beef heart mitochondrial ATPase, in both the membrane-bound and isolated form, contains tightly bound ATP and ADP. Each mol of ATPase contains about 2.2 mol ATP and 1.3 mol ADP. 2. In the absence of ATPase activity, these nucleotides exchange only slowly with nucleotides in solution. The exchange rate is increased during coupled ATPase activity, but not when the ATPase is uncoupled. 3. Oligomycin and dicyclohexylcarbodiimide inhibit exchange of the bound nucleotides, as does the ATPase inhibitor protein, although in each case some residual exchange occurs. Aurovertin, although inhibiting phosphorylation, does not inhibit the exchange. This is discussed in terms of the reversibility of these inhibitors. 4. The stimulation of exchange seen during coupled ATPase activity requires energisation of the ATPase molecule. Using the exchange reaction as a probe of energisation, it is deduced that energy can be transferred between different ATPase molecules. 5. It is proposed that coupled ATPase activity and phosphorylation in submitochondrial particles involve the tight nucleotide binding sites and the (weak) ATPase site, while uncoupled ATPase activity involves only the weak site.
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PMID:Tightly bound nucleotides of the energy-transducing ATPase, and their role in oxidative phosphorylation. II. The beef heart mitochondrial system. 13 63

1. Stimulation of the Escherichia coli ATPase activity by urea and trypsin shows that the ATPase activity both in the membrane-bound and the solubilized form is partly masked. 2. A protein, inhibiting the ATPase activity of Escherichia coli, can be isolated by sodium dodecyl sulphate polyacrylamide gel electrophoresis of purified ATPase. The inhibitor was identified with the smallest of the subunits of E. coli ATPase. 3. The molecular weight of the ATPase inhibitor is about 10,000, as determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis and deduced from the amino acid composition. 4. The inhibitory action is independent of pH, ionic strength or the presence of Mg2+ or ATP. 5. The ATPase inhibitor is heat-stable, insensitive to urea but very sensitive to trypsin degradation. 6. The Escherichia coli ATPase inhibitor does not inhibit the mitochondrial or the chloroplast ATPase.
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PMID:Isolation and characterization of an inhibitory subunit of the Mg2+--Ca2+-ATPase of Escherichia coli. 13 64

1. 8-Azido-ATP is a suitable photoaffinity label for beef-heart mitochondrial ATPase (F1) 2. 8-Azido-ATP is hydrolysed slowly by F1 in the dark. Photolysis at 350 nm in the presence of F1 leads to inhibition of the ATPase activity. The presence of ATP during illumination prevents the inhibition. Illumination of F1 in the absence of 8-azido-ATP causes no inhibition. 3. Added Mg2+ is not necessary for the binding of the 8-azido-ATP to F1. 4. 8-Azido-ATP binds specifically to the beta subunits of F1. 5. The ATPase activity is completely inhibited when 2 mol of 8-azido-ATP are bound per mol F1.
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PMID:Specific photolabelling of beef-heart mitochondrial ATPase by 8-azido-ATP. 13 19

Bicarbonate stimulation of hepatic mitochondrial ATPase activity decreased in rats subjected to intense physical training and reached minimum values at the end of the third week. The stimulatory effect of bicarbonate on mitochondrial heart ATPase remained unaffected under equal conditions. ATPase stimulation by dinitrophenol and sensitivity to oligomycin, both in mitochondria from rat liver or heart, were not affected by physical training. Results suggest that stimulation by dinitrophenol and bicarbonate might be due to effects on separate sites of the enzyme.
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PMID:Bicarbonate stimulation of mitochondrial ATPase. Effect of physical training. 14 Apr 43

Ligand-binding studies with labelled triethyltin on yeast mitochondrial membranes showed the presence of high-affinity sites (KD = 0.6 micronM; 1.2 +/- 0.3 nmol/mg of protein) and low-affinity sites (KD less than 45 micronM; 70 +/- 20 nmol/mg of protein). The dissociation constant of the high-affinity site is in good agreement with the concentration of triethyltin required for inhibition of mitochondrial ATPase (adenosine triphosphatase) and oxidative phosphorylation. The high-affinity site is not competed for by oligomycin or venturicidin, indicating that triethyltin reacts at a different site from these inhibitors of oxidative phosphorylation. Fractionation of the mitochondrial membrane shows a specific association of the high-affinity sites with the ATP synthase complex. During purification of ATP synthase (oligomycin-sensitive ATPase) there is a 5-6-fold purification of oligomycin- and triethyltin-sensitive ATPase activity concomitant with a 7-9-fold increase in high-affinity triethyltin-binding sites. The purified yeast oligomycin-sensitive ATPase complex contains approximately six binding sites for triethyltin/mol of enzyme complex. It is concluded that specific triethyltin-binding sites are components of the ATP synthase complex, which accounts for the specific inhibition of ATPase and oxidative phosphorylation by triethyltin.
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PMID:Studies of energy-linked reactions. Localization of the site of action of trialkyltin in yeast mitochondria. 14 Dec 73


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