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Showing 1 to 20 of 26 for “"Proton translocation"”.
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Proton Translocation in the Bacteriorhodopsin Photocycle
… we concluded that at low pH, the released proton is from the PRC as at neutral pH, but is delayed until the O to BR transition. The O to BR transition is rate-limited by the deprotonation of the PRC.
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Mechanisms of proton translocation in Methanosarcina mazei Gö1
… dieser Arbeit konnten drei unterschiedliche protonentranslozierende Enzymsysteme des methanogenen Archaeons Methanosarcina mazei Gö1 analysiert werden: Die F420H2:Heterodisulfid-Oxidoreduktase, die H2:Heterodisulfid-Oxidoreduktase sowie eine protonentranslozierende Pyrophosphatase.Es konnte …
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Relationships Between Proton Translocation, Absorption Changes, and Photocurrents in the Bacteriorhodopsin Photocycle
The mechanisms of proton release and uptake in bacteriorhodopsin (bR) were investigated using steady state and kinetic spectrophotometry and photocurrent methods. First, a kinetic model for the formation of the crucial M intermediate of the photocycle was formulated. The proposed model involved the …
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The role of respiration-dependent proton translocation in the acid tolerance of Gluconobacter oxydans
… solution suggested a NaCl-dependent flow of protons (H+) into the cells. Cells were then exposed to NaCI at pH 3.20 followed by the addition of glycerol to determine whether polyol oxidation resulted in H + explusion from the cells. Following glycerol addition, immediate acidification of the …
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Structural Characterization of F-type and V-type Rotary ATPases by Single Particle Electron Cryomicroscpy
… central rotor, which is powered by the flow of proton (or sometimes sodium ion) down the electrochemical gradient through the membrane-bound Fo/Vo region, leads to the chemical synthesis of ATP in F1/V1 region. The F1/V1 region, on the other hand, can catalyze ATP hydrolysis, which in turn leads …
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The Study of Aa3-Type Cytochrome C Oxidase in Rhodobacter Sphaeroides
… water and forms a transmembrane electrochemical proton gradient. This transmembrane gradient is used by ATP synthase to produce ATP. The oxygen chemistry reaction of the enzyme is coupled to a proton pump, which substantially contributes to the transmembrane electrochemical gradient. Two proton …
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The study of aa3-type cytochrome c oxidase in Rhodobacter sphaeroides
… water and forms a transmembrane electrochemical proton gradient. This transmembrane gradient is used by ATP synthase to produce ATP. The oxygen chemistry reaction of the enzyme is coupled to a proton pump, which substantially contributes to the transmembrane electrochemical gradient. Two proton …
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Kinetics and specificity of nicotinamide nucleotide binding to the dIII component of transhydrogenase from Rhodospirillum Rubrum
… of animal mitochondria. Using the energy of the proton electrochemical gradient (Δp), transhydrogenase translocates protons across the membrane whilst undergoing its redox reaction, in which hydride ion equivalents are transferred from NADH to NADP+ producing NAD+ and NADPH. Transhydrogenase …
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Cryo-electron microscopy studies on ovine mitochondrial complex I
… electron transfer between NADH and ubiquinone to proton translocation across the inner mitochondrial membrane, contributing to cellular energy production. Complex I is the largest and most elaborate protein assembly of the respiratory chain with a total mass of 970 kilodaltons. It consists of 14 …
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Structural Studies into the Mechanism and Organisation of Mammalian Respiratory Complex I
… chain and couples its redox activity with proton pumping across the inner mitochondrial membrane, thus contributing to the proton motive force which drives ATP synthesis. With single particle cryo-EM as a routine approach for high-resolution structure determination, there are extensive …
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Investigations of the mechanism of mitochondrial complex I by electron cryomicroscopy
… membrane, and couples the energy released to the translocation of four protons across the inner membrane, generating the proton motive force that powers vital cellular processes. The major question of how the energy liberated by NADH:ubiquinone oxidoreduction is captured and efficiently exploited …
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Paracoccus denitrificans as a model system for studying the mechanism of respiratory complex I
… NADH oxidation and ubiquinone reduction to the translocation of four protons across an energy-transducing membrane, contributing to the proton motive force used to synthesise ATP. Although structural knowledge of complex I is now extensive, the mechanisms by which it captures the redox energy …
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Studies of proton pumping mechanism in BA3 type cytochrome oxidase of thermus thermophilus and CBB3 type cytochrome oxidase of vibrio cholerae
… oxidoreductase superfamily are redox-driven proton pumps which couple the free energy liberated from the reduction of O2 to the translocation of protons across the membrane. The A-family requires two proton input channels (D- and K-channels) to transfer protons used for oxygen reduction …
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Infrared Spectroscopy of Cytochrome C Oxidase Intermediate States
… the process of cellular respiration, performing proton translocation coupled to the four-electron reduction of O2 to H2O. To accomplish this catalytic task, specific changes at the active site influence chemical and physical changes throughout the protein, altering amino acid side-chain …
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Current understanding on cytochrome bd quinol oxidase of Escherichia coli a mutagenesis, kinetics and spectroscopic study
… data further suggested a series of protonatable groups forming a proton channel located in the membrane to facilitate the proton translocation from cytoplasm to the heme b595 / heme d binuclear center. With help of the increasing database of available cytochrome bd oxidase sequences, …
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Study of the Yeast Vacuolar-type ATPase by Electron Cryomicroscopy
… of adenosine triphosphate (ATP) to pump protons across membranes and control the pH of many intracellular compartments. ATP hydrolysis in the soluble catalytic region of the enzyme is coupled to proton translocation through the membrane-bound region by rotation of a rotor subcomplex. …
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Structural and functional studies of mitochondrial NADH:ubiquinone oxidoreductase (complex I)
… and the reduction of ubiquinone, coupled to the translocation of protons across the mitochondrial inner membrane, maintaining the proton motive force used for ATP synthesis. Complex I is the least understood of the respiratory enzymes; although the mechanisms of NADH oxidation and intramolecular …
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Molecular Dynamics Simulations and Cross-Link Analysis of the Rotary Molecular Motor F(o) of ATP Synthase
… that couples the synthesis of ATP in F1 to the proton translocation across Fo which is driven by the electrochemical proton gradient across the membrane. F1 consists of three different subunits in the stoichiometry a1b2c10. So far, only the structure of the c-subunit and a partial structure of …
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Mutagenesis investigations into proton transfer pathways and control points in respiratory complex I
… from NADH to ubiquinone to transport four protons across an energy transducing membrane. The protons contribute to building the proton-motive force that powers oxidative phosphorylation, and the oxidation of NADH is crucial for NADH/NAD+ homeostasis, positioning complex I at a key control …
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Studies on assembly and genetic variation in mitochondrial respiratory complex I
… oxidoreductase) couples electron transfer to proton translocation across the inner mitochondrial membrane, to drive the synthesis of ATP. Its distinctive L-shaped structure comprises 45 subunits, encoded by both the mitochondrial and nuclear genomes, which are assembled by a complicated …
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