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 requirement of bovine heart mitochondrial oligomycin sensitivity conferring protein (OSCP) in conferring dicyclohexylcarbodiimide (DCCD)-sensitivity to membrane-bound F1 was investigated by using OSCP-depleted membrane fraction (UF0) of ATP synthase. The ATPase activity of UF0-F1 was completely insensitive to DCCD while that of UF0-F1-OSCP was inhibited 95% by 16 microM DCCD. Both UF0-F1 and UF0-F1-OSCP complexes bound 5 nmol [14C]DCCD/mg UF0, and all the radioactivity was found to be associated with the DCCD-binding proteolipid. The data suggest that OSCP may be necessary for transmitting not only energy-linked signals, but also signals induced by F0 inhibitory ligands in mitochondrial energy transduction.
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PMID:ATP synthase complex from bovine heart mitochondria: the oligomycin sensitivity conferring protein is essential for dicyclohexyl carbodiimide-sensitive ATPase. 183 60

Immunological studies were designed to study the structure of the oligomycin sensitivity conferring protein (OSCP) integrated in the mitochondrial ATPase-ATPsynthase complex. The monoclonal antibody 2B1B1 used in this study could bind as well to purified or membrane bound OSCP as shown previously by Protein A-gold immunocytochemistry and by competitive immunotitration. In this paper, it is shown that 2B1B1 can also immunoprecipitate the F0F1 complex from a Triton X-100 extract. This means that not only, 2B1B1 binds to the surface of OSCP but also that the binding of 2B1B1 did not destroy the interactions between F0 and F1 and further demonstrates the external location of the 2B1B1 binding site in the ATPase-ATPsynthase complex. This antigenic site was located on the N-terminal sequence of OSCP, between residues 1 and 72, as demonstrated after chemical cleavage of OSCP with formic acid, hydroxylamine and partial cleavage with cyanogen bromide. The proximity of Tyr and Arg to the epitope was suggested by the lack of 2B1B1 binding to iodinated OSCP and by the susceptibility of this binding to trypsin or to endoproteinase Arg-C treatments of OSCP, respectively. A more precise location of the epitope has been attempted by using the method of synthesis of overlapping octapeptides on solid support. It was found that 2 groups of octapeptides could bind 2B1B1. The first group contained in common the sequence Pro7-Pro8-Val9-Gln10-Ile11-Tyr12- and the second group of peptides contained the sequence Arg62-Ser63-Val64-Lys65. Another monoclonal antibody, AF4H7, which competes with 2B1B1, also recognized the first group of peptides. The possible involvement of these 2 fragments in the epitope localized at the surface of OSCP is discussed. In addition, secondary structure theoretical analysis predicts that these 2 domains should be in a beta-strand configuration.
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PMID:Epitope of OSCP oligomycin sensitivity conferring protein exposed at the surface of the mitochondrial ATPase-ATPsynthase complex. 247 97

Interactions between oligomycin sensitivity conferring protein (OSCP) and subunits of beef heart mitochondrial F1-ATPase have been explored by cross-linking at an OSCP/F1 molar ratio close to 1 to ensure specific high-affinity binding of OSCP to F1 [see Dupuis et al. [Dupuis, A., Issartel, J.-P., Lunardi, J., Satre, M., & Vignais, P.V. (1985) Biochemistry (preceding paper in this issue)]]. Cross-links between F1 subunits and OSCP were established by means of two zero length cross-linkers, 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide and N-(ethoxycarbonyl)-2-ethoxydihydroquinoline. The cross-linked products were separated by sodium dodecyl suflate-polyacrylamide gel electrophoresis. Coomassie blue staining revealed two cross-linked products of Mr 75 000 and 80 000 which could result from the binding of OSCP to the alpha and beta subunits of F1. Definite identification of the cross-linked products was achieved by chemical labeling with specific radiolabeled reagents and by blotting on nitrocellulose filters followed by immunocharacterization with anti-alpha, anti-beta, and anti-OSCP antibodies. OSCP was found to cross-link with the alpha and beta subunits of F1.
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PMID:Interactions between the oligomycin sensitivity conferring protein (OSCP) and beef heart mitochondrial F1-ATPase. 2. Identification of the interacting F1 subunits by cross-linking. 285 83

An azido derivative of the oligomycin sensitivity conferring protein (OSCP) was prepared by alkylation with the bifunctional reagent p-azido phenacyl bromide. Azido-OSCP was fully biologically active in the dark. Upon photoirradiation of a mixture of beef heart mitochondrial F1-ATPase and azido-OSCP, the resulting covalent photoproducts were separated by polyacrylamide gel electrophoresis in the presence of Na dodecyl sulfate and characterized by an immunochemical procedure. OSCP was found to react with the alpha and the beta subunits of F1 with strong preference for the alpha subunit.
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PMID:Photolabeling of mitochondrial F1-ATPase by an azido derivative of the oligomycin-sensitivity conferring protein. 286 14

The nature of mitochondrial PBC-related antigens has been investigated with radioimmunoassay (RIA) and immunoblotting methods. The major antigen(s) was located by RIA in beef heart mitochondria, submitochondrial particles, chloroform-extracted F1-ATPase and Complex III. Cross-competition RIA experiments showed that the same antigen is present in all the above samples but at different concentrations. The antigen is not present in purified F1-ATPase, cytochrome oxidase, the oligomycin sensitivity conferring protein (OSCP), Factor6, or the Transhydrogenase. Immunoblot analysis of the above mitochondrial proteins revealed two PBC-related antigens (apparent molecular weights of 70 KD and 60 KD) whose distribution in the various proteins and protein complexes correlated well with the antigens determined by RIA. Immunoblot analysis of mitochondrial antigens was carried out using sera from normal subjects and from patients with PBC and with different autoimmune diseases (AID). Only PBC sera reacted with the 70 KD and 60 KD antigens. The PBC antigen detected by RIA in submitochondrial particles and the chloroform-F1-ATPase could be blocked by Mersalyl, suggesting its relationship to the mitochondrial 'M2' antigen. Furthermore, the antigenicity of the 70 KD peptide was shown by immunoblotting to be dependent upon mercaptoethanol. Thus, not only is the antigenicity of the 70 KD component dependent on a sulphur group, but the sulphur must be in the reduced form.
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PMID:Primary biliary cirrhosis: further biochemical and immunological characterization of mitochondrial antigens. 286 43

The topographical organization of oligomycin sensitivity conferring protein (OSCP) in the mitochondrial adenosinetriphosphatase (ATPase)-ATP synthase complex has been studied. The accessibility of OSCP to monoclonal antibodies has been qualitatively visualized by using the protein A-gold electron microscopy immunocytochemistry or quantitatively estimated by immunotitration of OSCP in depolymerized or intact membranes. Besides, OSCP cannot be labeled by 3-(trifluoromethyl)-3-(m-[125I]iodophenyl)diazirine ([125I]TID) which selectively labels the hydrophobic core of membrane proteins. These observations demonstrate an external location of OSCP on the inner face of the inner mitochondrial membrane. The position of OSCP relative to other peptides of the complex has been analyzed by cross-linking experiments using either zero length N-(ethoxycarbonyl)-2-ethoxydihydroquinoline or 11-A span dimethyl suberimidate cross-linkers in the ATPase-ATP synthase complex. The OSCP cross-linked products were identified either by immunocharacterization with anti-alpha, anti-beta, or anti-OSCP monoclonal antibodies or by their molecular weight. OSCP was cross-linked with either the alpha- or beta-subunits of F1 or to a subunit of Mr 24 000. Other types of cross-linking were obtained by the labeling of OSCP with [cysteamine-35S]-N-succinimidyl 3-[[2-((2-nitro-4-azidophenyl)amino)ethyl]dithio]propionate ([35S]SNAP) and reconstitution of SNAP-OSCP with F1 in urea-treated submitochondrial particles. Under these conditions, OSCP is found to be adjacent to two other peptides of molecular weight close to 30 000. A comparison is made between the topology and the organization of the b-subunit of Escherichia coli and OSCP, suggesting an analogy between OSCP and the hydrophilic part of the b-subunit.
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PMID:Topography of oligomycin sensitivity conferring protein in the mitochondrial adenosinetriphosphatase-ATP synthase. 287 35

Beef heart mitchondrial oligomycin sensitivity conferring protein (OSCP) labeled with [14C]-N-ethylmaleimide ([14C]OSCP) at the only cysteine residue, Cys-118, present in the sequence [Ovchinnikov, Y. A., Modyanov, N. N., Grinkevich, V. A., Aldanova, N. A., Trubetskaya, O. E., Nazimov, I.V., Hundal, T., & Ernster, L. (1984) FEBS Lett. 166, 19-22] exhibits full biological activity in a reconstituted F0-F1 system [Dupuis, A., Issartel, J. P., Lunardi, J., Satre, M., & Vignais, P. V. (1985) Biochemistry 24, 728-733]. The binding parameters of [14C]OSCP with respect to the F0 sector of submitochondrial particles largely depleted of F1 and OSCP (AUA particles) have been explored. In the absence of added F1, a limited number of high-affinity OSCP binding sites were detected in the AUA particles (20-40 pmol/mg of particles); under these conditions, the low-affinity binding sites for OSCP were essentially not saturable. Addition of F1 to the particles promoted high-affinity binding for OSCP, with an apparent Kd of 5 nM, a value 16 times lower than the Kd relative to the binding of OSCP to F1 in the absence of particles. Saturation of the F1 and OSCP binding sites of AUA particles was attained with about 200 pmol of both F1 and OSCP added per milligram of particles. The oligomycin-dependent inhibition of F1-ATPase bound to AUA particles was assayed as a function of bound OSCP. At subsaturating concentrations of F1, the dose-effect curves were rectilinear until inhibition of ATPase activity by oligomycin was virtually complete, and maximal inhibition was obtained for an OSCP to F1 ratio of 1 (mol/mol).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interaction between the oligomycin sensitivity conferring protein and the F0 sector of the mitochondrial adenosinetriphosphatase complex: cooperative effect of the F1 sector. 288 78

Liver mitochondria from rats fed ethanol chronically demonstrated a 35% decrease in mitochondrial ATPase activity. Moreover, the ATPase activity was inhibited only 61% by addition of oligomycin. Treatment of mitochondria from ethanol-fed rats with the detergent, Lubrol-WX, caused the release of 36% of the F1 from the resulting inner membrane particles. In comparison, only 5% of the F1 was dissociated when control mitochondria were subjected to the Lubrol treatment. However, when the units of ATPase activity from the supernatant and particles obtained after Lubrol treatment were added together, their sums were equivalent in preparations from control and ethanol-fed animals. Moreover, polyacrylamide gel electrophoresis analyses indicated equal amounts of the alpha + beta subunits of F1 in mitochondria from control and ethanol-fed rats. Reconstitution experiments with urea particles and F1 prepared from both control and ethanol mitochondria revealed a decrease in oligomycin sensitivity which could be attributed to an alteration in the functioning of either the oligomycin sensitivity conferring protein or a membrane sector subunit that interacts with oligomycin. Analysis by reconstitution also demonstrated that there were no ethanol-elicited alterations in the properties of the F1 portion of the ATP synthase complex. These observations indicate that the activity of the ATP synthase complex is altered significantly by ethanol-elicited changes in the functioning of those polypeptides involved in modulating both oligomycin sensitivity and the association of F1 with membrane sector subunits.
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PMID:Ethanol-elicited alterations in the oligomycin sensitivity and structural stability of the mitochondrial F0 . F1 ATPase. 288 57

Oligomycin sensitivity conferral protein (OSCP), factor 6 (F6), and ATPase inhibitor protein are all components of the ATP synthase complex of bovine mitochondria. They are encoded in nuclear DNA. Complementary DNA clones encoding the precursors of these proteins have been isolated from a bovine library by using mixtures of synthetic oligonucleotides as hybridization probes, and their DNA sequences have been determined. The deduced protein sequences show that the OSCP, F6, and inhibitor proteins have N-terminal presequences of 23, 32, and 25 amino acids, respectively. These presequences are not present in the mature proteins. It is assumed that they serve to direct the proteins into the mitochondrial matrix. The cDNA clones have also been employed as hybridization probes to investigate the genetic complexity of the three proteins in cows and humans. These experiments indicate that the bovine and human inhibitor and bovine F6 proteins are encoded by single genes but suggest the possibility of the presence in both species of more than one gene (or pseudogenes) for the OSCP.
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PMID:ATP synthase from bovine mitochondria: sequences of imported precursors of oligomycin sensitivity conferral protein, factor 6, and adenosinetriphosphatase inhibitor protein. 289 43

In order to study the kinetics and the nature of the interactions between the oligomycin sensitivity conferring protein (OSCP) and the F0 and F1 sectors of the mitochondrial ATPase complex, fluorescent derivatives of OSCP, which are fully biologically active, have been prepared by reaction of OSCP with the following fluorescent thiol reagents: 6-acryloyl-2-(dimethylamino)naphthalene (acrylodan), 2-(4-maleimidylanilino)naphthalene-6-sulfonic acid (Mal-ANS), N-(1-pyrenyl)maleimide (Mal-pyrene), 7-(diethylamino)-3-(4-maleimidylphenyl)-4-methylcoumarin (Mal-coumarin), and fluorescein 5-maleimide (Mal-fluorescein). The preparation of these derivatives was based on the previous finding that the single cysteinyl residue of OSCP, Cys 118, can be covalently modified by alkylating reagents without loss of biological activity [Dupuis, A., Issartel, J. P., Lunardi, J., Satre, M., & Vignais, P. V. (1985) Biochemistry 24, 728-733]. For all fluorescent probes used, except Mal-pyrene and Mal-fluorescein, the emission spectra of conjugated OSCP were blue-shifted relative to those of the corresponding mercaptoethanol adducts, indicating that the fluorophores attached to Cys 118 were located in a hydrophobic pocket. These results were consistent with the high quantum yields and the increased fluorescence lifetimes of conjugated OSCP compared to mercaptoethanol adducts in aqueous buffer. They also fit with quenching data obtained with potassium iodide which showed that the fluorophore is shielded from the aqueous medium when it is attached to Cys 118 of OSCP. Especially noticeable was the wide half-width of the OSCP-acrylodan emission peak compared to that of mercaptoethanol-acrylodan.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Spectral properties of fluorescent derivatives of the oligomycin sensitivity conferring protein and analysis of their interaction with the F1 and F0 sectors of the mitochondrial ATPase complex. 290 94


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