Artículos de revistas: "F1 Fo ATP synthase"

1

Keller, David, Seema Singh, Paola Turina, Roderick Capaldi y Carlos Bustamante. "Structure of ATP synthase by SFM and single-particle image analysis". Proceedings, annual meeting, Electron Microscopy Society of America 53 (13 de agosto de 1995): 722–23. http://dx.doi.org/10.1017/s0424820100139986.

Texto completo

Resumen

F1Fo ATP synthases are the proteins responsible for the synthesis of ATP in oxidative phosphorylation, and are present in some form in all aerobic organisms, both prokaryotic and eukaryotic. They use the energy stored in a transmembrane proton gradient (which is generated by other members of the oxidative phosphorylation pathway) to synthesize ATP from ADP and Pi or, working in reverse, to pump protons across the membrane using the energy of ATP hydrolysis. The full protein has two sectors, F1 and Fo. F1 is normally bound to Fo (which is membrane integrated), but is water soluble when dissociated. The F1 sector contains the sites which bind ADP and catalyze its conversion to ATP. The Fo sector contains a channel which allows protons to to cross the membrane, dissipating the transmembrane chemical potential. By an unknown mechanism this translocation of protons through Fo is coupled to the hydrolysis or synthesis of ATP in F1, so that the energy released in hydrolysis of ATP can drive the motion of protons against an electrochemical potential, or the energy of translocating protons can be used to form high energy ADP-Pi bonds.

Los estilos APA, Harvard, Vancouver, ISO, etc.

2

Soga, Naoki, Kazuya Kimura, Kazuhiko Kinosita, Masasuke Yoshida y Toshiharu Suzuki. "Perfect chemomechanical coupling of FoF1-ATP synthase". Proceedings of the National Academy of Sciences 114, n.º 19 (25 de abril de 2017): 4960–65. http://dx.doi.org/10.1073/pnas.1700801114.

Texto completo

Resumen

FoF1-ATP synthase (FoF1) couples H+ flow in Fo domain and ATP synthesis/hydrolysis in F1 domain through rotation of the central rotor shaft, and the H+/ATP ratio is crucial to understand the coupling mechanism and energy yield in cells. Although H+/ATP ratio of the perfectly coupling enzyme can be predicted from the copy number of catalytic β subunits and that of H+ binding c subunits as c/β, the actual H+/ATP ratio can vary depending on coupling efficiency. Here, we report actual H+/ATP ratio of thermophilic Bacillus FoF1, whose c/β is 10/3. Proteoliposomes reconstituted with the FoF1 were energized with ΔpH and Δψ by the acid−base transition and by valinomycin-mediated diffusion potential of K+ under various [ATP]/([ADP]⋅[Pi]) conditions, and the initial rate of ATP synthesis/hydrolysis was measured. Analyses of thermodynamically equilibrated states, where net ATP synthesis/hydrolysis is zero, show linear correlation between the chemical potential of ATP synthesis/hydrolysis and the proton motive force, giving the slope of the linear function, that is, H+/ATP ratio, 3.3 ± 0.1. This value agrees well with the c/β ratio. Thus, chemomechanical coupling between Fo and F1 is perfect.

Los estilos APA, Harvard, Vancouver, ISO, etc.

3

Guo, Hui, Stephanie A. Bueler y John L. Rubinstein. "Atomic model for the dimeric FO region of mitochondrial ATP synthase". Science 358, n.º 6365 (26 de octubre de 2017): 936–40. http://dx.doi.org/10.1126/science.aao4815.

Texto completo

Resumen

Mitochondrial adenosine triphosphate (ATP) synthase produces the majority of ATP in eukaryotic cells, and its dimerization is necessary to create the inner membrane folds, or cristae, characteristic of mitochondria. Proton translocation through the membrane-embedded FO region turns the rotor that drives ATP synthesis in the soluble F1 region. Although crystal structures of the F1 region have illustrated how this rotation leads to ATP synthesis, understanding how proton translocation produces the rotation has been impeded by the lack of an experimental atomic model for the FO region. Using cryo–electron microscopy, we determined the structure of the dimeric FO complex from Saccharomyces cerevisiae at a resolution of 3.6 angstroms. The structure clarifies how the protons travel through the complex, how the complex dimerizes, and how the dimers bend the membrane to produce cristae.

Los estilos APA, Harvard, Vancouver, ISO, etc.

4

Kawai, Yoshiko, Maki Kaidoh, Yumiko Yokoyama y Toshio Ohhashi. "Cell surface F1/Fo ATP synthase contributes to interstitial flow-mediated development of the acidic microenvironment in tumor tissues". American Journal of Physiology-Cell Physiology 305, n.º 11 (1 de diciembre de 2013): C1139—C1150. http://dx.doi.org/10.1152/ajpcell.00199.2013.

Texto completo

Resumen

To address pivotal roles of cell surface F1/FO ATP synthase in the development of acidic microenvironment in tumor tissues, we investigated effects of shear stress stimulation on the cultured human breast cancer cells, MDA-MB-231 and MDA-MB-157, or human melanoma cells, SK-Mel-1. Shear stress stimulation (0.5–5.0 dyn/cm2), the levels of which are similar to those produced by the interstitial flow, induced strength-dependent corelease of ATP and H+ from the cells, which triggered CO2 gas excretion. In contrast, the same level of shear stress stimulation did not induce significant ATP release and CO2 gas excretion from the control human mammary epithelial cells (HMEC). Marked immunocytochemical and mRNA expression of cell surface F1/FO ATP synthase, vacuolar-ATPase (V-ATPase), carbonic anhydrase type IX, and ectonucleoside triphosphate diphosphohydrolase (ENTPDase) 3 were detected in MDA-MB-231 cells, but little or no expression on the HMEC. Pretreatment with cell surface F1/FO ATP synthase inhibitors, but not cell surface V-ATPase inhibitors, caused a significant reduction of the shear stress stimulation-mediated ATP release and CO2 gas excretion from MDA-MB-231 cells. The ENTPDase activity in the shear stress-loaded MDA-MB-231 cell culture medium supernatant increased significantly in a time-dependent manner. In addition, MDA-MB-231 cells displayed strong staining for purinergic 2Y1 (P2Y1) receptors on their surfaces, and the receptors partially colocalized with ENTPDase 3. These findings suggest that cell surface F1/FO ATP synthase, but not V-ATPase, may play key roles in the development of interstitial flow-mediated acidic microenvironment in tumor tissues through the shear stress stimulation-induced ATP and H+ corelease and CO2 gas production.

Los estilos APA, Harvard, Vancouver, ISO, etc.

5

Lippe, Giovanna, Gabriele Coluccino, Marco Zancani, Walter Baratta y Paola Crusiz. "Mitochondrial F-ATP Synthase and Its Transition into an Energy-Dissipating Molecular Machine". Oxidative Medicine and Cellular Longevity 2019 (15 de abril de 2019): 1–10. http://dx.doi.org/10.1155/2019/8743257.

Texto completo

Resumen

The mitochondrial F-ATP synthase is the principal energy-conserving nanomotor of cells that harnesses the proton motive force generated by the respiratory chain to make ATP from ADP and phosphate in a process known as oxidative phosphorylation. In the energy-converting membranes, F-ATP synthase is a multisubunit complex organized into a membrane-extrinsic F1 sector and a membrane-intrinsic FO domain, linked by central and peripheral stalks. Due to its essential role in the cellular metabolism, malfunction of F-ATP synthase has been associated with a variety of pathological conditions, and the enzyme is now considered as a promising drug target for multiple disease conditions and for the regulation of energy metabolism. We discuss structural and functional features of mitochondrial F-ATP synthase as well as several conditions that partially or fully inhibit the coupling between the F1 catalytic activities and the FO proton translocation, thus decreasing the cellular metabolic efficiency and transforming the enzyme into an energy-dissipating structure through molecular mechanisms that still remain to be defined.

Los estilos APA, Harvard, Vancouver, ISO, etc.

6

Eisel, Bianca, Felix W. W. Hartrampf, Thomas Meier y Dirk Trauner. "Reversible optical control of F1 Fo -ATP synthase using photoswitchable inhibitors". FEBS Letters 592, n.º 3 (febrero de 2018): 343–55. http://dx.doi.org/10.1002/1873-3468.12958.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

7

Rodríguez, Eliana y Magela Laviña. "The Proton Channel Is the Minimal Structure of ATP Synthase Necessary and Sufficient for Microcin H47 Antibiotic Action". Antimicrobial Agents and Chemotherapy 47, n.º 1 (enero de 2003): 181–87. http://dx.doi.org/10.1128/aac.47.1.181-187.2003.

Texto completo

Resumen

ABSTRACT It had been previously determined that the presence of FoF1 ATP synthase was required for microcin H47 antibiotic action. In this work, microcin-resistant atp mutants were genetically analyzed. Their mutations, originated by Tn5 insertion, in all cases were found to affect determinants for the Fo portion of ATP synthase. To discern if microcin action required the presence of the entire complex or if the Fo proton channel would suffice, recombinant plasmids carrying different segments of the atp operon were constructed and introduced into an atp deletion strain. The phenotypic analysis of the strains thus obtained clearly indicated that the presence of the Fo proton channel was absolutely required for microcin H47 action, while the F1 catalytic portion was found to be dispensable. Furthermore, when any of the three components of the proton channel was missing, total resistance to the antibiotic ensued. Complementation analysis between atp::Tn5 chromosomal mutations and recombinant atp plasmid constructions further supported the idea that the proton channel would be the minimal structure of the ATP synthase complex needed for microcin H47 antibiotic action.

Los estilos APA, Harvard, Vancouver, ISO, etc.

8

Cobley, James, Anna Noble, Rachel Bessell, Matthew Guille y Holger Husi. "Reversible Thiol Oxidation Inhibits the Mitochondrial ATP Synthase in Xenopus laevis Oocytes". Antioxidants 9, n.º 3 (5 de marzo de 2020): 215. http://dx.doi.org/10.3390/antiox9030215.

Texto completo

Resumen

Oocytes are postulated to repress the proton pumps (e.g., complex IV) and ATP synthase to safeguard mitochondrial DNA homoplasmy by curtailing superoxide production. Whether the ATP synthase is inhibited is, however, unknown. Here we show that: oligomycin sensitive ATP synthase activity is significantly greater (~170 vs. 20 nmol/min−1/mg−1) in testes compared to oocytes in Xenopus laevis (X. laevis). Since ATP synthase activity is redox regulated, we explored a regulatory role for reversible thiol oxidation. If a protein thiol inhibits the ATP synthase, then constituent subunits must be reversibly oxidised. Catalyst-free trans-cyclooctene 6-methyltetrazine (TCO-Tz) immunocapture coupled to redox affinity blotting reveals several subunits in F1 (e.g., ATP-α-F1) and Fo (e.g., subunit c) are reversibly oxidised. Catalyst-free TCO-Tz Click PEGylation reveals significant (~60%) reversible ATP-α-F1 oxidation at two evolutionary conserved cysteine residues (C244 and C294) in oocytes. TCO-Tz Click PEGylation reveals ~20% of the total thiols in the ATP synthase are substantially oxidised. Chemically reversing thiol oxidation significantly increased oligomycin sensitive ATP synthase activity from ~12 to 100 nmol/min−1/mg−1 in oocytes. We conclude that reversible thiol oxidation inhibits the mitochondrial ATP synthase in X. laevis oocytes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

9

Okazaki, Kei-ichi y Gerhard Hummer. "Elasticity, friction, and pathway of γ-subunit rotation in FoF1-ATP synthase". Proceedings of the National Academy of Sciences 112, n.º 34 (10 de agosto de 2015): 10720–25. http://dx.doi.org/10.1073/pnas.1500691112.

Texto completo

Resumen

We combine molecular simulations and mechanical modeling to explore the mechanism of energy conversion in the coupled rotary motors of FoF1-ATP synthase. A torsional viscoelastic model with frictional dissipation quantitatively reproduces the dynamics and energetics seen in atomistic molecular dynamics simulations of torque-driven γ-subunit rotation in the F1-ATPase rotary motor. The torsional elastic coefficients determined from the simulations agree with results from independent single-molecule experiments probing different segments of the γ-subunit, which resolves a long-lasting controversy. At steady rotational speeds of ∼1 kHz corresponding to experimental turnover, the calculated frictional dissipation of less than kBT per rotation is consistent with the high thermodynamic efficiency of the fully reversible motor. Without load, the maximum rotational speed during transitions between dwells is reached at ∼1 MHz. Energetic constraints dictate a unique pathway for the coupled rotations of the Fo and F1 rotary motors in ATP synthase, and explain the need for the finer stepping of the F1 motor in the mammalian system, as seen in recent experiments. Compensating for incommensurate eightfold and threefold rotational symmetries in Fo and F1, respectively, a significant fraction of the external mechanical work is transiently stored as elastic energy in the γ-subunit. The general framework developed here should be applicable to other molecular machines.

Los estilos APA, Harvard, Vancouver, ISO, etc.

10

Davies, Karen M. y Werner Kühlbrandt. "Structure of the catalytic F1 head of the F1-Fo ATP synthase from Trypanosoma brucei". Proceedings of the National Academy of Sciences 115, n.º 13 (9 de marzo de 2018): E2906—E2907. http://dx.doi.org/10.1073/pnas.1801103115.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

11

Börsch, Michael y Thomas M. Duncan. "Spotlighting motors and controls of single FoF1-ATP synthase". Biochemical Society Transactions 41, n.º 5 (23 de septiembre de 2013): 1219–26. http://dx.doi.org/10.1042/bst20130101.

Texto completo

Resumen

Subunit rotation is the mechanochemical intermediate for the catalytic activity of the membrane enzyme FoF1-ATP synthase. smFRET (single-molecule FRET) studies have provided insights into the step sizes of the F1 and Fo motors, internal transient elastic energy storage and controls of the motors. To develop and interpret smFRET experiments, atomic structural information is required. The recent F1 structure of the Escherichia coli enzyme with the ϵ-subunit in an inhibitory conformation initiated a study for real-time monitoring of the conformational changes of ϵ. The present mini-review summarizes smFRET rotation experiments and previews new smFRET data on the conformational changes of the CTD (C-terminal domain) of ϵ in the E. coli enzyme.

Los estilos APA, Harvard, Vancouver, ISO, etc.

12

Kühlbrandt, Werner. "Structure and Mechanisms of F-Type ATP Synthases". Annual Review of Biochemistry 88, n.º 1 (20 de junio de 2019): 515–49. http://dx.doi.org/10.1146/annurev-biochem-013118-110903.

Texto completo

Resumen

F1Fo ATP synthases produce most of the ATP in the cell. F-type ATP synthases have been investigated for more than 50 years, but a full understanding of their molecular mechanisms has become possible only with the recent structures of complete, functionally competent complexes determined by electron cryo-microscopy (cryo-EM). High-resolution cryo-EM structures offer a wealth of unexpected new insights. The catalytic F1 head rotates with the central γ-subunit for the first part of each ATP-generating power stroke. Joint rotation is enabled by subunit δ/OSCP acting as a flexible hinge between F1 and the peripheral stalk. Subunit a conducts protons to and from the c-ring rotor through two conserved aqueous channels. The channels are separated by ∼6 Å in the hydrophobic core of Fo, resulting in a strong local field that generates torque to drive rotary catalysis in F1. The structure of the chloroplast F1Fo complex explains how ATPase activity is turned off at night by a redox switch. Structures of mitochondrial ATP synthase dimers indicate how they shape the inner membrane cristae. The new cryo-EM structures complete our picture of the ATP synthases and reveal the unique mechanism by which they transform an electrochemical membrane potential into biologically useful chemical energy.

Los estilos APA, Harvard, Vancouver, ISO, etc.

13

KRENN, Bea E., Heinrich STROTMANN, Hendrika S. VAN WALRAVEN, Marijke J. C. SCHOLTS y Ruud KRAAYENHOF. "The ATP synthase γ subunit provides the primary site of activation of the chloroplast enzyme: experiments with a chloroplast-like Synechocystis 6803 mutant". Biochemical Journal 323, n.º 3 (1 de mayo de 1997): 841–45. http://dx.doi.org/10.1042/bj3230841.

Texto completo

Resumen

The activation characteristics of the F1Fo-ATP synthase (where F1 and Fo are the hydrophilic and membrane-bound parts respectively of the enzyme) from Synechocystis 6803 wild-type and a Synechocystis 6803 mutant with a chloroplast-like insertion in the γ subunit have been studied. Activation of the ATP synthase in wild-type and mutant membrane vesicles was performed by acid–base transition-induced generation of a proton motive force (ΔH+). Since the mutant containing the regulatory segment of the chloroplast γ subunit showed thiol-modulation (typical of the chloroplast enzyme), this segment is indeed involved in the regulation of enzyme activation. It is shown that the ATP synthase from Synechocystis 6803 wild type corresponds functionally to the reduced form of the chloroplast ATP synthase, in view of the low ΔH+ required for activation of the enzyme and the high stability of the active state. Both the cyanobacterial wild-type and mutant ATP synthases can be activated by methanol, which apparently does not require the presence of the γ subunit regulatory segment.

Los estilos APA, Harvard, Vancouver, ISO, etc.

14

Cook, Gregory M., Stefanie Keis, Hugh W. Morgan, Christoph von Ballmoos, Ulrich Matthey, Georg Kaim y Peter Dimroth. "Purification and Biochemical Characterization of the F1Fo-ATP Synthase from Thermoalkaliphilic Bacillus sp. Strain TA2.A1". Journal of Bacteriology 185, n.º 15 (1 de agosto de 2003): 4442–49. http://dx.doi.org/10.1128/jb.185.15.4442-4449.2003.

Texto completo

Resumen

ABSTRACT We describe here purification and biochemical characterization of the F1Fo-ATP synthase from the thermoalkaliphilic organism Bacillus sp. strain TA2.A1. The purified enzyme produced the typical subunit pattern of an F1Fo-ATP synthase on a sodium dodecyl sulfate-polyacrylamide gel, with F1 subunits α, β, γ, δ, and ε and Fo subunits a, b, and c. The subunits were identified by N-terminal protein sequencing and mass spectroscopy. A notable feature of the ATP synthase from strain TA2.A1 was its specific blockage in ATP hydrolysis activity. ATPase activity was unmasked by using the detergent lauryldimethylamine oxide (LDAO), which activated ATP hydrolysis >15-fold. This activation was the same for either the F1Fo holoenzyme or the isolated F1 moiety, and therefore latent ATP hydrolysis activity is an intrinsic property of F1. After reconstitution into proteoliposomes, the enzyme catalyzed ATP synthesis driven by an artificially induced transmembrane electrical potential (Δψ). A transmembrane proton gradient or sodium ion gradient in the absence of Δψ was not sufficient to drive ATP synthesis. ATP synthesis was eliminated by the electrogenic protonophore carbonyl cyanide m-chlorophenylhydrazone, while the electroneutral Na+/H+ antiporter monensin had no effect. Neither ATP synthesis nor ATP hydrolysis was stimulated by Na+ ions, suggesting that protons are the coupling ions of the ATP synthase from strain TA2.A1, as documented previously for mesophilic alkaliphilic Bacillus species. The ATP synthase was specifically modified at its c subunits by N,N′-dicyclohexylcarbodiimide, and this modification inhibited ATP synthesis.

Los estilos APA, Harvard, Vancouver, ISO, etc.

15

Sielaff, Hendrik, Henning Rennekamp, André Wächter, Hao Xie, Florian Hilbers, Katrin Feldbauer, Stanley D. Dunn, Siegfried Engelbrecht y Wolfgang Junge. "Domain compliance and elastic power transmission in rotary FOF1-ATPase". Proceedings of the National Academy of Sciences 105, n.º 46 (10 de noviembre de 2008): 17760–65. http://dx.doi.org/10.1073/pnas.0807683105.

Texto completo

Resumen

The 2 nanomotors of rotary ATP synthase, ionmotive FO and chemically active F1, are mechanically coupled by a central rotor and an eccentric bearing. Both motors rotate, with 3 steps in F1 and 10–15 in FO. Simulation by statistical mechanics has revealed that an elastic power transmission is required for a high rate of coupled turnover. Here, we investigate the distribution in the FOF1 structure of compliant and stiff domains. The compliance of certain domains was restricted by engineered disulfide bridges between rotor and stator, and the torsional stiffness (κ) of unrestricted domains was determined by analyzing their thermal rotary fluctuations. A fluorescent magnetic bead was attached to single molecules of F1 and a fluorescent actin filament to FOF1, respectively. They served to probe first the functional rotation and, after formation of the given disulfide bridge, the stochastic rotational motion. Most parts of the enzyme, in particular the central shaft in F1, and the long eccentric bearing were rather stiff (torsional stiffness κ > 750 pNnm). One domain of the rotor, namely where the globular portions of subunits γ and ε of F1 contact the c-ring of FO, was more compliant (κ ≅ 68 pNnm). This elastic buffer smoothes the cooperation of the 2 stepping motors. It is located were needed, between the 2 sites where the power strokes in FO and F1 are generated and consumed.

Los estilos APA, Harvard, Vancouver, ISO, etc.

16

Mnatsakanyan, Nelli, Marc Llaguno, Youshan Yang, Yangyang Yan, Fred Sigworth y Elizabeth Jonas. "P4-512: EXCITOTOXIC NEURONAL DEATH INDUCING MEGACHANNEL RESIDES IN MONOMERIC F1 FO ATP SYNTHASE". Alzheimer's & Dementia 15 (julio de 2019): P1509—P1510. http://dx.doi.org/10.1016/j.jalz.2019.08.058.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

17

Moser, T. L., D. J. Kenan, T. A. Ashley, J. A. Roy, M. D. Goodman, U. K. Misra, D. J. Cheek y S. V. Pizzo. "Endothelial cell surface F1-FO ATP synthase is active in ATP synthesis and is inhibited by angiostatin". Proceedings of the National Academy of Sciences 98, n.º 12 (29 de mayo de 2001): 6656–61. http://dx.doi.org/10.1073/pnas.131067798.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

18

Heazlewood, J. L., J. Whelan y A. H. Millar. "The products of the mitochondrial orf25 and orfB genes are FO components in the plant F1 FO ATP synthase". FEBS Letters 540, n.º 1-3 (20 de marzo de 2003): 201–5. http://dx.doi.org/10.1016/s0014-5793(03)00264-3.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

19

Deckers-Hebestreit, Gabriele. "Assembly of the Escherichia coli FoF1 ATP synthase involves distinct subcomplex formation". Biochemical Society Transactions 41, n.º 5 (23 de septiembre de 2013): 1288–93. http://dx.doi.org/10.1042/bst20130096.

Texto completo

Resumen

The ATP synthase (FoF1) of Escherichia coli couples the translocation of protons across the cytoplasmic membrane by Fo to ATP synthesis or hydrolysis in F1. Whereas good knowledge of the nanostructure and the rotary mechanism of the ATP synthase is at hand, the assembly pathway of the 22 polypeptide chains present in a stoichiometry of ab2c10α3β3γδϵ has so far not received sufficient attention. In our studies, mutants that synthesize different sets of FoF1 subunits allowed the characterization of individually formed stable subcomplexes. Furthermore, the development of a time-delayed in vivo assembly system enabled the subsequent synthesis of particular missing subunits to allow the formation of functional ATP synthase complexes. These observations form the basis for a model that describes the assembly pathway of the E. coli ATP synthase from pre-formed subcomplexes, thereby avoiding membrane proton permeability by a concomitant assembly of the open H+-translocating unit within a coupled FoF1 complex.

Los estilos APA, Harvard, Vancouver, ISO, etc.

20

Sielaff, Hendrik, Seiga Yanagisawa, Wayne D. Frasch, Wolfgang Junge y Michael Börsch. "Structural Asymmetry and Kinetic Limping of Single Rotary F-ATP Synthases". Molecules 24, n.º 3 (30 de enero de 2019): 504. http://dx.doi.org/10.3390/molecules24030504.

Texto completo

Resumen

F-ATP synthases use proton flow through the FO domain to synthesize ATP in the F1 domain. In Escherichia coli, the enzyme consists of rotor subunits γεc10 and stator subunits (αβ)3δab2. Subunits c10 or (αβ)3 alone are rotationally symmetric. However, symmetry is broken by the b2 homodimer, which together with subunit δa, forms a single eccentric stalk connecting the membrane embedded FO domain with the soluble F1 domain, and the central rotating and curved stalk composed of subunit γε. Although each of the three catalytic binding sites in (αβ)3 catalyzes the same set of partial reactions in the time average, they might not be fully equivalent at any moment, because the structural symmetry is broken by contact with b2δ in F1 and with b2a in FO. We monitored the enzyme’s rotary progression during ATP hydrolysis by three single-molecule techniques: fluorescence video-microscopy with attached actin filaments, Förster resonance energy transfer between pairs of fluorescence probes, and a polarization assay using gold nanorods. We found that one dwell in the three-stepped rotary progression lasting longer than the other two by a factor of up to 1.6. This effect of the structural asymmetry is small due to the internal elastic coupling.

Los estilos APA, Harvard, Vancouver, ISO, etc.

21

Kaim, Georg y Peter Dimroth. "ATP synthesis by the F1 Fo ATP synthase of Escherichia coli is obligatorily dependent on the electric potential". FEBS Letters 434, n.º 1-2 (28 de agosto de 1998): 57–60. http://dx.doi.org/10.1016/s0014-5793(98)00969-7.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

22

Tsunoda, Satoshi P., Robert Aggeler, Hiroyuki Noji, Kazuhiko Kinosita, Masasuke Yoshida y Roderick A. Capaldi. "Observations of rotation within the Fo F1 -ATP synthase: deciding between rotation of the Fo c subunit ring and artifact". FEBS Letters 470, n.º 3 (27 de marzo de 2000): 244–48. http://dx.doi.org/10.1016/s0014-5793(00)01336-3.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

23

Jia, Lixia, Mary K. Dienhart y Rosemary A. Stuart. "Oxa1 Directly Interacts with Atp9 and Mediates Its Assembly into the Mitochondrial F1Fo-ATP Synthase Complex". Molecular Biology of the Cell 18, n.º 5 (mayo de 2007): 1897–908. http://dx.doi.org/10.1091/mbc.e06-10-0925.

Texto completo

Resumen

The yeast Oxa1 protein is involved in the biogenesis of the mitochondrial oxidative phosphorylation (OXPHOS) machinery. The involvement of Oxa1 in the assembly of the cytochrome oxidase (COX) complex, where it facilitates the cotranslational membrane insertion of mitochondrially encoded COX subunits, is well documented. In this study we have addressed the role of Oxa1, and its sequence-related protein Cox18/Oxa2, in the biogenesis of the F1Fo-ATP synthase complex. We demonstrate that Oxa1, but not Cox18/Oxa2, directly supports the assembly of the membrane embedded Fo-sector of the ATP synthase. Oxa1 was found to physically interact with newly synthesized mitochondrially encoded Atp9 protein in a posttranslational manner and in a manner that is not dependent on the C-terminal, matrix-localized region of Oxa1. The stable manner of the Atp9-Oxa1 interaction is in contrast to the cotranslational and transient interaction previously observed for the mitochondrially encoded COX subunits with Oxa1. In the absence of Oxa1, Atp9 was observed to assemble into an oligomeric complex containing F1-subunits, but its further assembly with subunit 6 (Atp6) of the Fo-sector was perturbed. We propose that by directly interacting with newly synthesized Atp9 in a posttranslational manner, Oxa1 is required to maintain the assembly competence of the Atp9-F1-subcomplex for its association with Atp6.

Los estilos APA, Harvard, Vancouver, ISO, etc.

24

Das, Amaresh y Lars G. Ljungdahl. "Clostridium pasteurianum F1Fo ATP Synthase: Operon, Composition, and Some Properties". Journal of Bacteriology 185, n.º 18 (15 de septiembre de 2003): 5527–35. http://dx.doi.org/10.1128/jb.185.18.5527-5535.2003.

Texto completo

Resumen

ABSTRACT The atp operon encoding F1Fo ATP synthase in the fermentative obligate anaerobic bacterium Clostridium pasteurianum was sequenced. It consisted of nine genes arranged in the order atpI(i), atpB(a), atpE(c), atpF(b), atpH(δ), atpA(α), atpG(γ), atpD(β), and atpC(ε), which was identical to that found in many bacteria. Reverse transcription-PCR confirmed the presence of the transcripts of all nine genes. The amount of ATPase activity in the membranes of C. pasteurianum was low compared to what has been found in many other bacteria. The F1Fo complexes solubilized from membranes of C. pasteurianum and Escherichia coli had similar masses, suggesting similar compositions for the F1Fo complexes from the two bacteria. Western blotting experiments with antibodies raised against the purified subunits of F1Fo detected the presence of eight subunits, α, β, γ, δ, ε, a, b, and c, in the F1Fo complex from C. pasteurianum. The F1Fo complex from C. pasteurianum was activated by thiocyanate, cyanate, or sulfhydryl compounds; inhibited by sulfite, bisulfite, or bicarbonate; and had tolerance to inhibition by dicyclohexylcarbodiimide. The target of thiol activation of the F1Fo complex from C. pasteurianum was F1. Thiocyanate and sulfite were noncompetitive with respect to substrate Mg ATP but competitive with respect to each other. The F1 and Fo parts of the F1Fo complexes from C. pasteurianum and E. coli bound to each other, but the hybrid F1Fo complexes were not functionally active.

Los estilos APA, Harvard, Vancouver, ISO, etc.

25

Kawai, Yoshiko, Kazuo Yoshida, Maki Kaidoh, Yumiko Yokoyama y Toshio Ohhashi. "Shear stress-mediated F1/FO ATP synthase-dependent CO2 gas excretion from human pulmonary arteriolar endothelial cells". Journal of Cellular Physiology 227, n.º 5 (23 de enero de 2012): 2059–68. http://dx.doi.org/10.1002/jcp.22937.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

26

Deckers-Hebestreit, G. y K. Altendorf. "The Fo complex of the proton-translocating F-type ATPase of Escherichia coli." Journal of Experimental Biology 172, n.º 1 (1 de noviembre de 1992): 451–59. http://dx.doi.org/10.1242/jeb.172.1.451.

Texto completo

Resumen

The ATP synthase (F1Fo) of Escherichia coli consists of two structurally and functionally distinct entities. The F1 part is composed of five subunits alpha, beta, gamma, delta and epsilon (3:3:1:1:1) and carries the catalytic centres of the enzyme. The membrane-bound Fo complex functions as a proton channel and consists of the three subunits a, b and c (1:2:10 +/- 1). Subunit c (8288 M(r)) exhibits a hairpin-like structure within the membrane. A conserved acidic residue (Asp-61) in the C-terminal hydrophobic segment is absolutely required for proton translocation through Fo, whereas the hydrophilic loop region is necessary for F1 binding. Expression of the chloroplast proteolipid together with subunits a and b of E. coli did not produce an active Fo hybrid complex. Therefore, the construction of hybrid c subunits consisting of parts of the proteolipid from both organisms is in progress to determine those parts of subunit c that are essential for a functional interplay with subunits a and b. Subunit a (30,276 M(r)), which is also involved in proton translocation, is an extremely hydrophobic protein with 5-8 membrane-spanning helices. Studies with alkaline phosphatase fusion proteins resulted in controversial conclusions about the localization of the N and C termini of the protein. A foreign epitope (13 amino acids) has been inserted into the N- or C-terminal region of subunit a without affecting the function of Fo. Binding studies with a monoclonal antibody against this epitope are now under investigation to determine the orientation of subunit a.(ABSTRACT TRUNCATED AT 250 WORDS)

Los estilos APA, Harvard, Vancouver, ISO, etc.

27

Mccarty, RE. "A PLANT BIOCHEMIST'S VIEW OF H+-ATPases AND ATP SYNTHASES." Journal of Experimental Biology 172, n.º 1 (1 de noviembre de 1992): 431–41. http://dx.doi.org/10.1242/jeb.172.1.431.

Texto completo

Resumen

My twenty-five year fascination with membrane ATPases grew out of my experiences in the laboratories of André Jagendorf and Efraim Racker. André introduced me to photosynthetic phosphorylation and Ef, to whose memory this article is dedicated, convinced me that ATPases had much to do with ATP synthesis. Astounding progress has been made in the H+-ATPase field in just two decades. By the early 1970s, it was generally recognized that oxidative and photosynthetic ATP synthesis were catalyzed by membrane enzymes that could act as H+-ATPases and that the common intermediate between electron transport and phosphorylation is the electrochemical proton gradient. At that time, it had been shown that a cation-stimulated ATPase activity was associated with plasma membrane preparations from plant roots. The endomembrane or vacuolar ATPases were unknown. The application of improved biochemical methods for membrane isolation and purification, as well as membrane protein reconstitutions, led rapidly to the conclusion that there are three major classes of membrane H+-ATPases, P, V and F. P-ATPases, which will not be considered further in this article, are phosphorylated during their catalytic cycle and have a much simpler polypeptide composition than V- or F-ATPases. The plasma membrane H+-ATPase of plant, yeasts and fungal cells is one example of this class of enzymes (see Pedersen and Carafoli, 1987, for a comparison of plasma membrane ATPases). Biochemical and gene sequencing analysis have revealed that V- and F-ATPases resemble each other structurally, but are distinct in function and origin. The 'V' stands for vacuolar and the 'F' for F1Fo. F1 was the first factor isolated from bovine heart mitochondria shown to be required for oxidative phosphorylation. Fo was so named because it is a factor that conferred oligomycin sensitivity to soluble F1. Other F-ATPases are often named to indicate their sources. For example, chloroplast F1 is denoted CF1 (see Racker, 1965, for early work on F1). Recent successes in reconstitution of vacuolar ATPase have led to a V1Vo nomenclature for this enzyme as well. The term 'ATP synthase' is now in general use to describe F-ATPases. This term emphasizes the facts that although F-ATPases function to synthesize ATP, they do not catalyze, normally, ATP hydrolysis linked to proton flux. In contrast, V-ATPases are very unlikely to operate as ATP synthases. Thus, F-ATPases are proton gradient consumers, whereas V-ATPases generate proton gradients at the expense of hydrolysis. In this brief review, I will compare the structures of F- and V-ATPases. Also, I give some insight into the mechanisms that help prevent wasteful ATP hydrolysis by the chloroplast ATP synthase (CF1Fo).

Los estilos APA, Harvard, Vancouver, ISO, etc.

28

Atlante, Anna y Daniela Valenti. "A Walk in the Memory, from the First Functional Approach up to Its Regulatory Role of Mitochondrial Bioenergetic Flow in Health and Disease: Focus on the Adenine Nucleotide Translocator". International Journal of Molecular Sciences 22, n.º 8 (17 de abril de 2021): 4164. http://dx.doi.org/10.3390/ijms22084164.

Texto completo

Resumen

The mitochondrial adenine nucleotide translocator (ANT) plays the fundamental role of gatekeeper of cellular energy flow, carrying out the reversible exchange of ADP for ATP across the inner mitochondrial membrane. ADP enters the mitochondria where, through the oxidative phosphorylation process, it is the substrate of Fo-F1 ATP synthase, producing ATP that is dispatched from the mitochondrion to the cytoplasm of the host cell, where it can be used as energy currency for the metabolic needs of the cell that require energy. Long ago, we performed a method that allowed us to monitor the activity of ANT by continuously detecting the ATP gradually produced inside the mitochondria and exported in the extramitochondrial phase in exchange with externally added ADP, under conditions quite close to a physiological state, i.e., when oxidative phosphorylation takes place. More than 30 years after the development of the method, here we aim to put the spotlight on it and to emphasize its versatile applicability in the most varied pathophysiological conditions, reviewing all the studies, in which we were able to observe what really happened in the cell thanks to the use of the “ATP detecting system” allowing the functional activity of the ANT-mediated ADP/ATP exchange to be measured.

Los estilos APA, Harvard, Vancouver, ISO, etc.

29

Aquila, G., G. Morciano, D. De Marco, D. Preti, G. Pedriali, C. Trapella, G. Campo, P. Rizzo y P. Pinton. "C subunit of F1/FO-ATP synthase as target for preventing the detrimental effect of myocardial ischemia/reperfusion injury". Vascular Pharmacology 103-105 (abril de 2018): 47. http://dx.doi.org/10.1016/j.vph.2017.12.003.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

30

Pante, Eric, Vanessa Becquet, Amélia Viricel y Pascale Garcia. "Investigation of the molecular signatures of selection on ATP synthase genes in the marine bivalve Limecola balthica". Aquatic Living Resources 32 (2019): 3. http://dx.doi.org/10.1051/alr/2019001.

Texto completo

Resumen

We used transcriptomic sequence data to describe patterns of divergence and selection across different populations of a marine bivalve (Limecola balthica). Our analyses focused on a nuclear gene (atp5c1) that was previously detected in an FST scan as highly structured among populations separated by the Finistère Peninsula in France. This gene encodes the gamma subunit of the FO/F1 ATP synthase, a multi-protein complex that is paramount to cellular respiration and energy production. Analysis of non-synonymous to synonymous mutation ratios revealed that 65% of the gene is highly conserved (dN/dS ≤ 0.1, min = 0), while 6% of the gene is likely under positive selection (dN/dS ≥ 1, max = 2.03). All replacement mutations are clustered on a 46 residues portion of the protein, within an inter-peptide interaction zone. Comparative genomics suggests that these mutations are evolutionarily stable, and we hypothesize that they are involved in inter-population genetic incompatibilities with other subunits of the ATP synthase complex. The protein stability of the gamma subunit conferred by southern variants was inferred to be higher under warmer temperatures, suggesting that environmental conditions may contribute to the strength of genetic barriers in L. balthica.

Los estilos APA, Harvard, Vancouver, ISO, etc.

31

He, Jiuya, Holly C. Ford, Joe Carroll, Corsten Douglas, Evvia Gonzales, Shujing Ding, Ian M. Fearnley y John E. Walker. "Assembly of the membrane domain of ATP synthase in human mitochondria". Proceedings of the National Academy of Sciences 115, n.º 12 (12 de febrero de 2018): 2988–93. http://dx.doi.org/10.1073/pnas.1722086115.

Texto completo

Resumen

The ATP synthase in human mitochondria is a membrane-bound assembly of 29 proteins of 18 kinds. All but two membrane components are encoded in nuclear genes, synthesized on cytoplasmic ribosomes, and imported into the matrix of the organelle, where they are assembled into the complex with ATP6 and ATP8, the products of overlapping genes in mitochondrial DNA. Disruption of individual human genes for the nuclear-encoded subunits in the membrane portion of the enzyme leads to the formation of intermediate vestigial ATPase complexes that provide a description of the pathway of assembly of the membrane domain. The key intermediate complex consists of the F1-c8 complex inhibited by the ATPase inhibitor protein IF1 and attached to the peripheral stalk, with subunits e, f, and g associated with the membrane domain of the peripheral stalk. This intermediate provides the template for insertion of ATP6 and ATP8, which are synthesized on mitochondrial ribosomes. Their association with the complex is stabilized by addition of the 6.8 proteolipid, and the complex is coupled to ATP synthesis at this point. A structure of the dimeric yeast Fo membrane domain is consistent with this model of assembly. The human 6.8 proteolipid (yeast j subunit) locks ATP6 and ATP8 into the membrane assembly, and the monomeric complexes then dimerize via interactions between ATP6 subunits and between 6.8 proteolipids (j subunits). The dimers are linked together back-to-face by DAPIT (diabetes-associated protein in insulin-sensitive tissue; yeast subunit k), forming long oligomers along the edges of the cristae.

Los estilos APA, Harvard, Vancouver, ISO, etc.

32

Lippe, G., F. Dabbeni Sala y M. C. Sorgato. "ATP synthase complex from beef heart mitochondria. Role of the thiol group of the 25-kDa subunit of Fo in the coupling mechanism between Fo and F1." Journal of Biological Chemistry 263, n.º 35 (diciembre de 1988): 18627–34. http://dx.doi.org/10.1016/s0021-9258(18)37331-9.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

33

Salani, Barbara, Silvia Ravera, Patrizia Fabbi, Silvano Garibaldi, Mario Passalacqua, Claudio Brunelli, Davide Maggi, Renzo Cordera y Pietro Ameri. "Glibenclamide Mimics Metabolic Effects of Metformin in H9c2 Cells". Cellular Physiology and Biochemistry 43, n.º 3 (2017): 879–90. http://dx.doi.org/10.1159/000481638.

Texto completo

Resumen

Background: Sulfonylureas, such as glibenclamide, are antidiabetic drugs that stimulate beta-cell insulin secretion by binding to the sulfonylureas receptors (SURs) of adenosine triphosphate-sensitive potassium channels (KATP). Glibenclamide may be also cardiotoxic, this effect being ascribed to interference with the protective function of cardiac KATP channels for which glibenclamide has high affinity. Prompted by recent evidence that glibenclamide impairs energy metabolism of renal cells, we investigated whether this drug also affects the metabolism of cardiac cells. Methods: The cardiomyoblast cell line H9c2 was treated for 24 h with glibenclamide or metformin, a known inhibitor of the mitochondrial respiratory chain. Cell viability was evaluated by sulforodhamine B assay. ATP and AMP were measured according to the enzyme coupling method and oxygen consumption by using an amperometric electrode, while Fo-F1 ATP synthase activity assay was evaluated by chemiluminescent method. Protein expression was measured by western blot. Results: Glibenclamide deregulated energy balance of H9c2 cardiomyoblasts in a way similar to that of metformin. It inhibited mitochondrial complexes I, II and III with ensuing impairment of oxygen consumption and ATP synthase activity, ATP depletion and increased AMPK phosphorylation. Furthermore, glibenclamide disrupted mitochondrial subcellular organization. The perturbation of mitochondrial energy balance was associated with enhanced anaerobic glycolysis, with increased activity of phosphofructo kinase, pyruvate kinase and lactic dehydrogenase. Interestingly, some additive effects of glibenclamide and metformin were observed. Conclusions: Glibenclamide deeply alters cell metabolism in cardiac cells by impairing mitochondrial organization and function. This may further explain the risk of cardiovascular events associated with the use of this drug, alone or in combination with metformin.

Los estilos APA, Harvard, Vancouver, ISO, etc.

34

Nath, Sunil. "A Novel Conceptual Model for the Dual Role of FOF1-ATP Synthase in Cell Life and Cell Death". Biomolecular Concepts 11, n.º 1 (22 de agosto de 2020): 143–52. http://dx.doi.org/10.1515/bmc-2020-0014.

Texto completo

Resumen

AbstractThe mitochondrial permeability transition (MPT) has been one of the longstanding enigmas in biology. Its cause is currently at the center of an extensive scientific debate, and several hypotheses on its molecular nature have been put forward. The present view holds that the transition arises from the opening of a high-conductance channel in the energy-transducing membrane, the permeability transition pore (PTP), also called the mitochondrial megachannel or the multiconductance channel (MMC). Here, the novel hypothesis is proposed that the aqueous access channels at the interface of the c-ring and the a-subunit of FO in the FOF1-ATP synthase are repurposed during induction of apoptosis and constitute the elusive PTP/ MMC. A unifying principle based on regulation by local potentials is advanced to rationalize the action of the myriad structurally and chemically diverse inducers and inhibitors of PTP/MMC. Experimental evidence in favor of the hypothesis and its differences from current models of PTP/MMC are summarized. The hypothesis explains in considerable detail how the binding of Ca2+ to a β-catalytic site (site 3) in the F1 portion of ATP synthase triggers the opening of the PTP/MMC. It is also shown to connect to longstanding proposals within Nath’s torsional mechanism of energy transduction and ATP synthesis as to how the binding of MgADP to site 3 does not induce PTP/MMC, but instead catalyzes physiological ATP synthesis in cell life. In the author’s knowledge, this is the first model that explains how Ca2+ transforms the FOF1-ATP synthase from an exquisite energy-conserving enzyme in cell life into an energy-dissipating structure that promotes cell death. This has major implications for basic as well as for clinical research, such as for the development of drugs that target the MPT, given the established role of PTP/MMC dysregulation in cancer, ischemia, cardiac hypertrophy, and various neurodegenerative diseases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

35

Baker, Nicola, Graham Hamilton, Jonathan M. Wilkes, Sebastian Hutchinson, Michael P. Barrett y David Horn. "Vacuolar ATPase depletion affects mitochondrial ATPase function, kinetoplast dependency, and drug sensitivity in trypanosomes". Proceedings of the National Academy of Sciences 112, n.º 29 (6 de julio de 2015): 9112–17. http://dx.doi.org/10.1073/pnas.1505411112.

Texto completo

Resumen

Kinetoplastid parasites cause lethal diseases in humans and animals. The kinetoplast itself contains the mitochondrial genome, comprising a huge, complex DNA network that is also an important drug target. Isometamidium, for example, is a key veterinary drug that accumulates in the kinetoplast in African trypanosomes. Kinetoplast independence and isometamidium resistance are observed where certain mutations in the F1-γ-subunit of the two-sector F1Fo-ATP synthase allow for Fo-independent generation of a mitochondrial membrane potential. To further explore kinetoplast biology and drug resistance, we screened a genome-scale RNA interference library in African trypanosomes for isometamidium resistance mechanisms. Our screen identified 14 V-ATPase subunits and all 4 adaptin-3 subunits, implicating acidic compartment defects in resistance; V-ATPase acidifies lysosomes and related organelles, whereas adaptin-3 is responsible for trafficking among these organelles. Independent strains with depleted V-ATPase or adaptin-3 subunits were isometamidium resistant, and chemical inhibition of the V-ATPase phenocopied this effect. While drug accumulation in the kinetoplast continued after V-ATPase subunit depletion, acriflavine-induced kinetoplast loss was specifically tolerated in these cells and in cells depleted for adaptin-3 or endoplasmic reticulum membrane complex subunits, also identified in our screen. Consistent with kinetoplast dispensability, V-ATPase defective cells were oligomycin resistant, suggesting ATP synthase uncoupling and bypass of the normal Fo-A6-subunit requirement; this subunit is the only kinetoplast-encoded product ultimately required for viability in bloodstream-form trypanosomes. Thus, we describe 30 genes and 3 protein complexes associated with kinetoplast-dependent growth. Mutations affecting these genes could explain natural cases of dyskinetoplasty and multidrug resistance. Our results also reveal potentially conserved communication between the compartmentalized two-sector rotary ATPases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

36

Morelli, Alessandro M., Silvia Ravera, Daniela Calzia y Isabella Panfoli. "Hypothesis of Lipid-Phase-Continuity Proton Transfer for Aerobic ATP Synthesis". Journal of Cerebral Blood Flow & Metabolism 33, n.º 12 (2 de octubre de 2013): 1838–42. http://dx.doi.org/10.1038/jcbfm.2013.175.

Texto completo

Resumen

The basic processes harvesting chemical energy for life are driven by proton (H+) movements. These are accomplished by the mitochondrial redox complex V, integral membrane supramolecular aggregates, whose structure has recently been described by advanced studies. These did not identify classical aqueous pores. It was proposed that H+ transfer for oxidative phosphorylation (OXPHOS) does not occur between aqueous sources and sinks, where an energy barrier would be insurmountable. This suggests a novel hypothesis for the proton transfer. A lipid-phase-continuity H+ transfer is proposed in which H+ are always bound to phospholipid heads and cardiolipin, according to Mitchell's hypothesis of asymmetric vectorial H+ diffusion. A phase separation is proposed among the proton flow, following an intramembrane pathway, and the ATP synthesis, occurring in the aqueous phase. This view reminiscent of Grotthus mechanism would better account for the distance among the Fo and F1 moieties of FoF1–ATP synthase, for its mechanical coupling, as well as the necessity of a lipid membrane. A unique active role for lipids in the evolution of life can be envisaged. Interestingly, this view would also be consistent with the evidence of an OXPHOS outside mitochondria also found in non-vesicular membranes, housing the redox complexes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

37

Claggett, Shane B., Mac O'Neil Plancher, Stanley D. Dunn y Brian D. Cain. "The b Subunits in the Peripheral Stalk of F1F0 ATP Synthase Preferentially Adopt an Offset Relationship". Journal of Biological Chemistry 284, n.º 24 (15 de abril de 2009): 16531–40. http://dx.doi.org/10.1074/jbc.m109.002980.

Texto completo

Resumen

The peripheral stalk of F1F0 ATP synthase is essential for the binding of F1 to FO and for proper transfer of energy between the two sectors of the enzyme. The peripheral stalk of Escherichia coli is composed of a dimer of identical b subunits. In contrast, photosynthetic organisms express two b-like genes that form a heterodimeric peripheral stalk. Previously we generated chimeric peripheral stalks in which a portion of the tether and dimerization domains of the E. coli b subunits were replaced with homologous sequences from the b and b′ subunits of Thermosynechococcus elongatus (Claggett, S. B., Grabar, T. B., Dunn, S. D., and Cain, B. D. (2007) J. Bacteriol. 189, 5463–5471). The spatial arrangement of the chimeric b and b′ subunits, abbreviated Tb and Tb′, has been investigated by Cu2+-mediated disulfide cross-link formation. Disulfide formation was studied both in soluble model polypeptides and between full-length subunits within intact functional F1F0 ATP synthase complexes. In both cases, disulfides were preferentially formed between TbA83C and Tb′A90C, indicating the existence of a staggered relationship between helices of the two chimeric subunits. Even under stringent conditions rapid formation of disulfides between these positions occurred. Importantly, formation of this cross-link had no detectable effect on ATP-driven proton pumping, indicating that the staggered conformation is compatible with normal enzymatic activity. Under less stringent reaction conditions, it was also possible to detect b subunits cross-linked through identical positions, suggesting that an in-register, nonstaggered parallel conformation may also exist.

Los estilos APA, Harvard, Vancouver, ISO, etc.

38

P�lissier, P., N. Camougrand, G. Velours y M. Gu�rin. "NCA3, a nuclear gene involved in the mitochondrial expression of subunits 6 and 8 of the Fo-F1 ATP synthase of S. cerevisiae". Current Genetics 27, n.º 5 (abril de 1995): 409–16. http://dx.doi.org/10.1007/bf00311209.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

39

Lin, Jung-Hsin. "Mechanical Transmission Between the γ-Subunit of F1 and the C-Ring of Membrane-Bound FO of ATP Synthase: A Molecular Dynamics Study". Biophysical Journal 102, n.º 3 (enero de 2012): 712a. http://dx.doi.org/10.1016/j.bpj.2011.11.3861.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

40

Cross, Richard L. y Lincoln Taiz. "Gene duplication as a means for altering H+ /ATP ratios during the evolution of Fo F1 ATPases and synthases". FEBS Letters 259, n.º 2 (1 de enero de 1990): 227–29. http://dx.doi.org/10.1016/0014-5793(90)80014-a.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

41

Kurochkin, Ilya O., Markus Etzkorn, David Buchwalter, Larry Leamy y Inna M. Sokolova. "Top-down control analysis of the cadmium effects on molluscan mitochondria and the mechanisms of cadmium-induced mitochondrial dysfunction". American Journal of Physiology-Regulatory, Integrative and Comparative Physiology 300, n.º 1 (enero de 2011): R21—R31. http://dx.doi.org/10.1152/ajpregu.00279.2010.

Texto completo

Resumen

Cadmium (Cd) is a toxic metal and an important environmental pollutant that can strongly affect mitochondrial function and bioenergetics in animals. We investigated the mechanisms of Cd action on mitochondrial function of a marine mollusk (the eastern oyster Crassostrea virginica ) by performing a top-down control analysis of the three major mitochondrial subsystems (substrate oxidation, proton leak, and phosphorylation). Our results showed that the substrate oxidation and proton leak subsystems are the main targets for Cd toxicity in oyster mitochondria. Exposure to 12.5 μM Cd strongly inhibited the substrate oxidation subsystem and stimulated the proton conductance across the inner mitochondrial membrane. Proton conductance was also elevated and substrate oxidation inhibited by Cd in the presence of a mitochondrially targeted antioxidant, MitoVitE, indicating that Cd effects on these subsystems were to a large extent ROS independent. Cd did not affect the kinetics of the phosphorylation system, indicating that it has negligible effects on F1, FO ATP synthase and/or the adenine nucleotide transporter in oyster mitochondria. Cd exposure altered the patterns of control over mitochondrial respiration, increasing the degree of control conferred by the substrate oxidation subsystem, especially in resting (state 4) mitochondria. Taken together, these data suggest that Cd-induced decrease of mitochondrial efficiency and ATP production are predominantly driven by the high sensitivity of substrate oxidation and proton leak subsystems to this metal.

Los estilos APA, Harvard, Vancouver, ISO, etc.

42

Pogoryelov, Denys, Christian Reichen, Adriana L. Klyszejko, René Brunisholz, Daniel J. Muller, Peter Dimroth y Thomas Meier. "The Oligomeric State of c Rings from Cyanobacterial F-ATP Synthases Varies from 13 to 15". Journal of Bacteriology 189, n.º 16 (1 de junio de 2007): 5895–902. http://dx.doi.org/10.1128/jb.00581-07.

Texto completo

Resumen

ABSTRACT We isolated the c rings of F-ATP synthases from eight cyanobacterial strains belonging to four different taxonomic classes (Chroococcales, Nostocales, Oscillatoriales, and Gloeobacteria). These c rings showed different mobilities on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), probably reflecting their molecular masses. This supposition was validated with the previously characterized c11, c14, and c15 rings, which migrated on SDS-PAGE in proportion to their molecular masses. Hence, the masses of the cyanobacterial c rings can conveniently be deduced from their electrophoretic mobilities and, together with the masses of the c monomers, allow the calculation of the c ring stoichiometries. The method is a simple and fast way to determine stoichiometries of SDS-stable c rings and hence a convenient means to unambiguously determine the ion-to-ATP ratio, a parameter reflecting the bioenergetic efficacy of F-ATP synthases. AFM imaging was used to prove the accuracy of the method and confirmed that the c ring of Synechococcus elongatus SAG 89.79 is a tridecameric oligomer. Despite the high conservation of the c-subunit sequences from cyanobacterial strains from various environmental groups, the stoichiometries of their c rings varied between c13 and c15. This systematic study of the c-ring stoichiometries suggests that variability of c-ring sizes might represent an adaptation of the individual cyanobacterial species to their particular environmental and physiological conditions. Furthermore, the two new examples of c15 rings underline once more that an F1/Fo symmetry mismatch is not an obligatory feature of all F-ATP synthases.

Los estilos APA, Harvard, Vancouver, ISO, etc.

43

Morciano, Giampaolo, Delia Preti, Gaia Pedriali, Giorgio Aquila, Sonia Missiroli, Anna Fantinati, Natascia Caroccia et al. "Discovery of Novel 1,3,8-Triazaspiro[4.5]decane Derivatives That Target the c Subunit of F1/FO-Adenosine Triphosphate (ATP) Synthase for the Treatment of Reperfusion Damage in Myocardial Infarction". Journal of Medicinal Chemistry 61, n.º 16 (30 de julio de 2018): 7131–43. http://dx.doi.org/10.1021/acs.jmedchem.8b00278.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

44

Kawai, Yoshiko, Kumiko Ajima, Maki Kaidoh, Masao Sakaguchi, Satoshi Tanaka, Mikito Kawamata, Hiroko Kimura y Toshio Ohhashi. "In vivo support for the new concept of pulmonary blood flow-mediated CO2 gas excretion in the lungs". American Journal of Physiology-Lung Cellular and Molecular Physiology 308, n.º 12 (15 de junio de 2015): L1224—L1236. http://dx.doi.org/10.1152/ajplung.00205.2014.

Texto completo

Resumen

To further examine the validity of the proposed concept of pulmonary blood flow-dependent CO2 gas excretion in the lungs, we investigated the effects of intramediastinal balloon catheterization-, pulmonary artery catheterization-, or isoprenaline (ISP)-induced changes in pulmonary blood flow on the end-expiratory CO2 gas pressure (PeCO2), the maximal velocity of the pulmonary artery (Max Vp), systemic arterial pressure, and heart rate of anesthetized rabbits. We also evaluated the changes in the PeCO2 in clinical models of anemia or pulmonary embolism. An almost linear relationship was detected between the PeCO2 and Max Vp. In an experiment in which small pulmonary arteries were subjected to stenosis, the PeCO2 fell rapidly, and the speed of the reduction was dependent on the degree of stenosis. ISP produced significant increases in the PeCO2 of the anesthetized rabbits. Conversely, treatment with piceatannol or acetazolamide induced significant reductions in the PeCO2. Treatment with a cell surface F1/FO ATP synthase antibody caused significant reductions in the PeCO2 itself and the ISP-induced increase in the PeCO2. Neither the PeCO2 nor SAP was significantly influenced by marked anemia [%hematocrit (Ht), 70∼47%]. On the other hand, in the presence of less severe anemia (%Ht: 100∼70%) both the PeCO2 and SAP fell significantly when the rabbits' blood viscosity was decreased. The rabbits in which pulmonary embolisms were induced demonstrated significantly reduced PeCO2 values, which was compatible with the lowering of their Max Vp. In conclusion, we reaffirm the validity of the proposed concept of CO2 gas exchange in the lungs.

Los estilos APA, Harvard, Vancouver, ISO, etc.

45

Joshi, Saroj, Gong-Jie Cao, Cheryl Nath y Jyotsna Shah. "Oligomycin Sensitivity Conferring Protein of Mitochondrial ATP Synthase: Deletions in the N-Terminal End Cause Defects in Interactions with F1, while Deletions in the C-Terminal End Cause Defects in Interactions with Fo†". Biochemistry 35, n.º 37 (enero de 1996): 12094–103. http://dx.doi.org/10.1021/bi9612327.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

46

Wagner, Karina, Inge Perschil, Christiane D. Fichter y Martin van der Laan. "Stepwise Assembly of Dimeric F1Fo-ATP Synthase in Mitochondria Involves the Small Fo-Subunits k and i". Molecular Biology of the Cell 21, n.º 9 (mayo de 2010): 1494–504. http://dx.doi.org/10.1091/mbc.e09-12-1023.

Texto completo

Resumen

F1Fo-ATP synthase is a key enzyme of oxidative phosphorylation that is localized in the inner membrane of mitochondria. It uses the energy stored in the proton gradient across the inner mitochondrial membrane to catalyze the synthesis of ATP from ADP and phosphate. Dimeric and higher oligomeric forms of ATP synthase have been observed in mitochondria from various organisms. Oligomerization of ATP synthase is critical for the morphology of the inner mitochondrial membrane because it supports the generation of tubular cristae membrane domains. Association of individual F1Fo-ATP synthase complexes is mediated by the membrane-embedded Fo-part. Several subunits were mapped to monomer-monomer-interfaces of yeast ATP synthase complexes, but only Su e (Atp21) and Su g (Atp20) have so far been identified as crucial for the formation of stable dimers. We show that two other small Fo-components, Su k (Atp19) and Su i (Atp18) are involved in the stepwise assembly of F1Fo-ATP synthase dimers and oligomers. We have identified an intermediate form of the ATP synthase dimer, which accumulates in the absence of Su i. Moreover, our data indicate that Su i facilitates the incorporation of newly synthesized subunits into ATP synthase complexes.

Los estilos APA, Harvard, Vancouver, ISO, etc.

47

Anello, Marcello, Daniela Spampinato, Salvatore Piro, Francesco Purrello y Agata Maria Rabuazzo. "Glucosamine-induced alterations of mitochondrial function in pancreatic β-cells: possible role of protein glycosylation". American Journal of Physiology-Endocrinology and Metabolism 287, n.º 4 (octubre de 2004): E602—E608. http://dx.doi.org/10.1152/ajpendo.00320.2003.

Texto completo

Resumen

Chronic exposure of rat pancreatic islets and INS-1 insulinoma cells to glucosamine (GlcN) produced a reduction of glucose-induced (22.2 mM) insulin release that was associated with a reduction of ATP levels and ATP/ADP ratio compared with control groups. To further evaluate mitochondrial function and ATP metabolism, we then studied uncoupling protein-2 (UCP2), F1-F0-ATP-synthase, and mitochondrial membrane potential, a marker of F1-F0-ATP-synthase activity. UCP2 protein levels were unchanged after chronic exposure to GlcN on both pancreatic islets and INS-1 β-cells. Due to the high number of cells required to measure mitochondrial F1-F0-ATP-synthase protein levels and mitochondrial membrane potential, we used INS-1 cells, and we found that chronic culture with GlcN increased F1-F0-ATP-synthase protein levels but decreased glucose-stimulated changes of mitochondrial membrane potential. Moreover, F1-F0-ATP-synthase was highly glycosylated, as demonstrated by experiments with N-glycosidase F and glycoprotein staining. Tunicamycin (an inhibitor of protein N-glycosylation), when added with GlcN in the culture medium, was able to partially prevent all these negative effects on insulin secretion, adenine nucleotide content, mitochondrial membrane potential, and protein glycosylation. Thus we suggest that GlcN-induced pancreatic β-cell toxicity might be mediated by reduced cell energy production. An excessive protein N-glycosylation of mitochondrial F1-F0-ATP-synthase might lead to cell damage and secretory alterations in pancreatic β-cells.

Los estilos APA, Harvard, Vancouver, ISO, etc.

48

Griffiths, D. K. "ATP SYNTHASE: INTRINSIC CATIONS OF SUBUNIT-c & FO". Biochemical Society Transactions 28, n.º 5 (1 de octubre de 2000): A188. http://dx.doi.org/10.1042/bst028a188c.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

49

Hejzlarová, Kateřina, Vilma Kaplanová, Hana Nůsková, Nikola Kovářová, Pavel Ješina, Zdeněk Drahota, Tomáš Mráček, Sara Seneca y Josef Houštěk. "Alteration of structure and function of ATP synthase and cytochrome c oxidase by lack of Fo-a and Cox3 subunits caused by mitochondrial DNA 9205delTA mutation". Biochemical Journal 466, n.º 3 (6 de marzo de 2015): 601–11. http://dx.doi.org/10.1042/bj20141462.

Texto completo

Resumen

Mutations in the MT-ATP6 gene are frequent causes of severe mitochondrial disorders. Typically, these are missense mutations, but another type is represented by the 9205delTA microdeletion, which removes the stop codon of the MT-ATP6 gene and affects the cleavage site in the MT-ATP8/MT-ATP6/MT-CO3 polycistronic transcript. This interferes with the processing of mRNAs for the Atp6 (Fo-a) subunit of ATP synthase and the Cox3 subunit of cytochrome c oxidase (COX). Two cases described so far presented with strikingly different clinical phenotypes–mild transient lactic acidosis or fatal encephalopathy. To gain more insight into the pathogenic mechanism, we prepared 9205delTA cybrids with mutation load ranging between 52 and 99% and investigated changes in the structure and function of ATP synthase and the COX. We found that 9205delTA mutation strongly reduces the levels of both Fo-a and Cox3 proteins. Lack of Fo-a alters the structure but not the content of ATP synthase, which assembles into a labile, ∼60 kDa smaller, complex retaining ATP hydrolytic activity but which is unable to synthesize ATP. In contrast, lack of Cox3 limits the biosynthesis of COX but does not alter the structure of the enzyme. Consequently, the diminished mitochondrial content of COX and non-functional ATP synthase prevent most mitochondrial ATP production. The biochemical effects caused by the 9205delTA microdeletion displayed a pronounced threshold effect above ∼90% mutation heteroplasmy. We observed a linear relationship between the decrease in subunit Fo-a or Cox3 content and the functional presentation of the defect. Therefore we conclude that the threshold effect originated from a gene–protein level.

Los estilos APA, Harvard, Vancouver, ISO, etc.

50

Weber, Joachim y Alan E. Senior. "ATP synthesis driven by proton transport in F1 F0 -ATP synthase". FEBS Letters 545, n.º 1 (18 de abril de 2003): 61–70. http://dx.doi.org/10.1016/s0014-5793(03)00394-6.

Texto completo

Los estilos APA, Harvard, Vancouver, ISO, etc.

Artículos de revistas sobre el tema "F1 Fo ATP synthase"

Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros