Difference between revisions of "Quarato 2011 Biochim Biophys Acta"
Beno Marija (talk | contribs) |
|||
Line 6: | Line 6: | ||
|journal=Biochim Biophys Acta | |journal=Biochim Biophys Acta | ||
|abstract=The metabolic control analysis was applied to digitonin-permeabilized HepG2 cell line to assess the flux control exerted by cytochrome c oxidase on the mitochondrial respiration. Experimental conditions eliciting different energy/respiratory states in mitochondria were settled. The results obtained show that the mitochondrial electrochemical potential accompanies a depressing effect on the control coefficient exhibited by the [[Complex_IV|cytochrome c oxidase]]. Both the components of the protonmotive force, i.e. the voltage (ΔΨ(m)) and the proton (ΔpH(m)) gradient, displayed a similar effect. Quantitative estimation of the ΔΨ(m) unveiled that the voltage-dependent effect on the control coefficient of cytochrome c oxidase takes place sharply in a narrow range of membrane potential from 170-180 to 200-210 mV consistent with the physiologic transition from [[State 3]] to [[State 4]] of respiration. Extension of the metabolic flux control analysis to the NADH dehydrogenase and bc(1) complexes of the mitochondrial [[respiratory chain]] resulted in a similar effect. A mechanistic model is put forward whereby the respiratory chain complexes are proposed to exist in a voltage-mediated threshold-controlled dynamic equilibrium between supercomplexed and isolated states. | |abstract=The metabolic control analysis was applied to digitonin-permeabilized HepG2 cell line to assess the flux control exerted by cytochrome c oxidase on the mitochondrial respiration. Experimental conditions eliciting different energy/respiratory states in mitochondria were settled. The results obtained show that the mitochondrial electrochemical potential accompanies a depressing effect on the control coefficient exhibited by the [[Complex_IV|cytochrome c oxidase]]. Both the components of the protonmotive force, i.e. the voltage (ΔΨ(m)) and the proton (ΔpH(m)) gradient, displayed a similar effect. Quantitative estimation of the ΔΨ(m) unveiled that the voltage-dependent effect on the control coefficient of cytochrome c oxidase takes place sharply in a narrow range of membrane potential from 170-180 to 200-210 mV consistent with the physiologic transition from [[State 3]] to [[State 4]] of respiration. Extension of the metabolic flux control analysis to the NADH dehydrogenase and bc(1) complexes of the mitochondrial [[respiratory chain]] resulted in a similar effect. A mechanistic model is put forward whereby the respiratory chain complexes are proposed to exist in a voltage-mediated threshold-controlled dynamic equilibrium between supercomplexed and isolated states. | ||
|keywords=metabolic control analysis, oxidative phosphorylation, mitochondrial membrane potential, cytochrome c oxidase respiratory chain supercomplexes | |keywords=metabolic control analysis, oxidative phosphorylation, mitochondrial membrane potential, cytochrome c oxidase respiratory chain supercomplexes, HepG2 | ||
|mipnetlab=IT_Foggia_Capitanio N | |mipnetlab=IT_Foggia_Capitanio N | ||
}} | }} | ||
{{Labeling | {{Labeling | ||
|area=Respiration | |||
|organism=Human, Mouse | |organism=Human, Mouse | ||
|tissues=Liver, Fibroblast | |tissues=Liver, Fibroblast | ||
|preparations=Intact cells | |preparations=Intact cells | ||
|couplingstates=OXPHOS | |couplingstates=LEAK, OXPHOS | ||
|pathways=N, S | |||
|instruments=Oxygraph-2k | |instruments=Oxygraph-2k | ||
}} | }} |
Latest revision as of 09:56, 8 November 2017
Quarato G, Piccoli C, Scrima R, Capitanio N (2011) Variation of flux control coefficient of cytochrome c oxidase and of the other respiratory chain complexes at different values of protonmotive force occurs by a threshold mechanism. Biochim Biophys Acta 1807: 1114-1124. |
Quarato G, Piccoli C, Scrima R, Capitanio N (2011) Biochim Biophys Acta
Abstract: The metabolic control analysis was applied to digitonin-permeabilized HepG2 cell line to assess the flux control exerted by cytochrome c oxidase on the mitochondrial respiration. Experimental conditions eliciting different energy/respiratory states in mitochondria were settled. The results obtained show that the mitochondrial electrochemical potential accompanies a depressing effect on the control coefficient exhibited by the cytochrome c oxidase. Both the components of the protonmotive force, i.e. the voltage (ΔΨ(m)) and the proton (ΔpH(m)) gradient, displayed a similar effect. Quantitative estimation of the ΔΨ(m) unveiled that the voltage-dependent effect on the control coefficient of cytochrome c oxidase takes place sharply in a narrow range of membrane potential from 170-180 to 200-210 mV consistent with the physiologic transition from State 3 to State 4 of respiration. Extension of the metabolic flux control analysis to the NADH dehydrogenase and bc(1) complexes of the mitochondrial respiratory chain resulted in a similar effect. A mechanistic model is put forward whereby the respiratory chain complexes are proposed to exist in a voltage-mediated threshold-controlled dynamic equilibrium between supercomplexed and isolated states. • Keywords: metabolic control analysis, oxidative phosphorylation, mitochondrial membrane potential, cytochrome c oxidase respiratory chain supercomplexes, HepG2
• O2k-Network Lab: IT_Foggia_Capitanio N
Labels: MiParea: Respiration
Organism: Human, Mouse
Tissue;cell: Liver, Fibroblast
Preparation: Intact cells
Coupling state: LEAK, OXPHOS
Pathway: N, S
HRR: Oxygraph-2k