Difference between revisions of "Dalmonte 2009 J Biol Chem"
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{{Publication | {{Publication | ||
|title=Dalmonte ME, Forte E, Genova ML, Giuffrè A, Sarti P, Lenaz G (2009) Control of respiration by cytochrome c oxidase in intact cells: role of the membrane potential. J Biol Chem 284: 32331-32335. | |title=Dalmonte ME, Forte E, Genova ML, Giuffrè A, Sarti P, Lenaz G (2009) Control of respiration by cytochrome c oxidase in intact cells: role of the membrane potential. J Biol Chem 284: 32331-32335. | ||
|info=[http://www.ncbi.nlm.nih.gov/pubmed/19776013 PMID: 19776013] | |info=[http://www.ncbi.nlm.nih.gov/pubmed/19776013 PMID: 19776013 Open Access] | ||
|authors=Dalmonte ME, Forte E, Genova ML, Giuffre A, Sarti P, Lenaz G | |authors=Dalmonte ME, Forte E, Genova ML, Giuffre A, Sarti P, Lenaz G | ||
|year=2009 | |year=2009 | ||
|journal=J | |journal=J Biol Chem | ||
|abstract=Metabolic control analysis was applied to intact HepG2 cells. The effect on the control coefficient of cytochrome ''c'' oxidase (C''c''OX) over cell respiration of both the electrical (Δψ) and chemical (ΔpH) component of the mitochondrial transmembrane proton electrochemical gradient (ΔμH+) was investigated. The overall O<sub>2</sub> consumption and specific C''c''OX activity of actively phosphorylating cells were titrated with cyanide under conditions in which Δψ and ΔpH were selectively modulated by addition of ionophores. In the absence of ionophores, C''c''OX displayed a high control coefficient (CIV = 0.73), thus representing an important site of regulation of mitochondrial oxidative phosphorylation. A high control coefficient value (CIV = 0.85) was also measured in the presence of nigericin, i.e. when Δψ is maximal, and in the presence of nigericin and valinomycin (CIV = 0.77), when ΔμH+ is abolished. In contrast, C''c''OX displayed a markedly lower control coefficient (CIV = 0.30) upon addition of valinomycin, when Δψ is converted into ΔpH. These results show that Δψ is responsible for the tight control of C''c''OX over respiration in actively phosphorylating cells. | |abstract=Metabolic control analysis was applied to intact HepG2 cells. The effect on the control coefficient of cytochrome ''c'' oxidase (C''c''OX) over cell respiration of both the electrical (Δψ) and chemical (ΔpH) component of the mitochondrial transmembrane proton electrochemical gradient (ΔμH+) was investigated. The overall O<sub>2</sub> consumption and specific C''c''OX activity of actively phosphorylating cells were titrated with cyanide under conditions in which Δψ and ΔpH were selectively modulated by addition of ionophores. In the absence of ionophores, C''c''OX displayed a high control coefficient (CIV = 0.73), thus representing an important site of regulation of mitochondrial oxidative phosphorylation. A high control coefficient value (CIV = 0.85) was also measured in the presence of nigericin, i.e. when Δψ is maximal, and in the presence of nigericin and valinomycin (CIV = 0.77), when ΔμH+ is abolished. In contrast, C''c''OX displayed a markedly lower control coefficient (CIV = 0.30) upon addition of valinomycin, when Δψ is converted into ΔpH. These results show that Δψ is responsible for the tight control of C''c''OX over respiration in actively phosphorylating cells. | ||
|keywords=Nigericin, Valinomycin, Cytochrome C oxidase, Membrane potential | |keywords=Nigericin, Valinomycin, Cytochrome C oxidase, Membrane potential | ||
Revision as of 17:20, 13 March 2013
| Dalmonte ME, Forte E, Genova ML, Giuffrè A, Sarti P, Lenaz G (2009) Control of respiration by cytochrome c oxidase in intact cells: role of the membrane potential. J Biol Chem 284: 32331-32335. |
Dalmonte ME, Forte E, Genova ML, Giuffre A, Sarti P, Lenaz G (2009) J Biol Chem
Abstract: Metabolic control analysis was applied to intact HepG2 cells. The effect on the control coefficient of cytochrome c oxidase (CcOX) over cell respiration of both the electrical (Δψ) and chemical (ΔpH) component of the mitochondrial transmembrane proton electrochemical gradient (ΔμH+) was investigated. The overall O2 consumption and specific CcOX activity of actively phosphorylating cells were titrated with cyanide under conditions in which Δψ and ΔpH were selectively modulated by addition of ionophores. In the absence of ionophores, CcOX displayed a high control coefficient (CIV = 0.73), thus representing an important site of regulation of mitochondrial oxidative phosphorylation. A high control coefficient value (CIV = 0.85) was also measured in the presence of nigericin, i.e. when Δψ is maximal, and in the presence of nigericin and valinomycin (CIV = 0.77), when ΔμH+ is abolished. In contrast, CcOX displayed a markedly lower control coefficient (CIV = 0.30) upon addition of valinomycin, when Δψ is converted into ΔpH. These results show that Δψ is responsible for the tight control of CcOX over respiration in actively phosphorylating cells. • Keywords: Nigericin, Valinomycin, Cytochrome C oxidase, Membrane potential
• O2k-Network Lab: IT Roma Sarti P, IT Bologna Lenaz G
Labels:
Organism: Human, Rat
Tissue;cell: Liver
Preparation: Intact Cell; Cultured; Primary"Intact Cell; Cultured; Primary" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property.
Enzyme: Complex IV; Cytochrome c Oxidase"Complex IV; Cytochrome c Oxidase" is not in the list (Adenine nucleotide translocase, Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase, Inner mt-membrane transporter, Marker enzyme, Supercomplex, TCA cycle and matrix dehydrogenases, ...) of allowed values for the "Enzyme" property.
HRR: Oxygraph-2k
