Difference between revisions of "Gnaiger 2018 EBEC2018"
Ā |
|||
(9 intermediate revisions by the same user not shown) | |||
Line 5: | Line 5: | ||
|year=2018 | |year=2018 | ||
|event=EBEC2018 Budapest HU | |event=EBEC2018 Budapest HU | ||
|abstract=ā.. ''the sum of the '''electrical pressure difference''' and the '''osmotic pressure difference''' (i.e. the electrochemical potential difference) of protons''ā [1] links to non-ohmic flux-force relationships between proton leak and protonmotive force | |abstract=ā.. ''the sum of the '''electrical pressure difference''' and the '''osmotic pressure difference''' (i.e. the electrochemical potential difference) of protons''ā [1] links to non-ohmic flux-force relationships between proton leak and protonmotive force ''pmF''. This is experimentally established, has direct consequences on mitochondrial physiology, but is theoretically little understood [2,3]. Here I distinguish pressure from potential differences (diffusion: Ī''Ī¼''<sub>H<sup>+</sup></sub> or Ī<sub>d</sub>''F''<sub>H<sup>+</sup></sub>; electric: Ī''ĪØ'' or Ī<sub>el</sub>''F''<sub>p<sup>+</sup></sub>), to explain non-ohmic flux-'''[[force]]''' relationships on the basis of four thermodynamic theorems. (''1'') Einsteinās diffusion equation [4] explains the [[concentration]] gradient (d'''''c'''''/d'''''z''''') in Fickās law as the product of chemical potential gradient (the vector force and resistance determine the velocity '''''v''''' of a particle) and local concentration '''''c'''''. This yields the chemical [[pressure]] gradient (vanāt Hoff): d<sub>'''d'''</sub>'''''Ī '''''/d'''''z''''' = ''RT''ād'''''c'''''/'''d''z'''''. [[Flux]] [5] is the product of '''''v''''' and '''''c'''''; '''''c''''' varies with force. Therefore, flux-force relationships are non-linear. (''2'') The ''pmF'' is not a vector force; the gradient is replaced by a pressure difference, and local concentration by a distribution function or free activity ''Ī±''. Flux is a function of ''Ī±'' and force, ''J''<sub>d</sub> = -''u''<sub>d</sub>ā''Ī±''āĪ<sub>d</sub>''F<sub>X</sub>'' = -''u''<sub>d</sub>āĪ<sub>d</sub>''Ī <sub>X</sub>'' [6]. (''3'') At Ī<sub>el</sub>''F''<sub>p<sup>+</sup></sub> = -Ī<sub>d</sub>''F''<sub>H</sub>+, the diffusion pressure of protons, Ī<sub>d</sub>''Ī ''<sub>H</sub>+ = ''RT''āĪ''c''<sub>H</sub>+ [Pa=Jām<sup>-3</sup>] is balanced by electric pressure, maintained by counterions of H<sup>+</sup>. Diffusional and electric pressures are isomorphic, additive, and yield protonmotive pressure ''pmp''. (''4'') The dependence of [[proton leak]] on ''pmF'' varies with Ī<sub>el</sub>''F''<sub>p<sup>+</sup></sub> versus Ī<sub>d</sub>''F''<sub>H</sub>+, in agreement with experimental evidence. The flux-force relationship is concave at high mitochondrial volume fractions, but near-exponential at small mt-matrix volume ratios. Linear flux-''pmp'' relationships imply a near-exponential dependence of the proton leak on the ''pmF'' ([7]; added 2022-07-04). | ||
|editor=[[Gnaiger E]] | |editor=[[Gnaiger E]] | ||
|mipnetlab=AT Innsbruck Gnaiger E | |||
}} | }} | ||
== Affiliations == | == Affiliations == | ||
::::#D. Swarovski Research Lab, Dept Visceral, Transplant Thoracic Surgery, Medical Univ Innsbruck | ::::# D. Swarovski Research Lab, Dept Visceral, Transplant Thoracic Surgery, Medical Univ Innsbruck | ||
::::#Oroboros Instruments | ::::# Oroboros Instruments | ||
::::::Innsbruck, Austria. - [email protected] | :::::: Innsbruck, Austria. - [email protected] | ||
== References == | == References == | ||
:::# Mitchell P (1966) Chemiosmotic coupling in oxidative and photosynthetic phosphorylation. Glynn Research, Bodmin. Biochim Biophys Acta Bioenergetics 1807:1507-38. - [[Mitchell 2011 Biochim Biophys Acta |Ā»Bioblast linkĀ«]] | |||
:::# Garlid KD, Beavis AD, Ratkje SK (1989) On the nature of ion leaks in energy-transducing membranes. Biochim Biophys Acta 976:109-20. - [[Garlid 1989 Biochim Biophys Acta |Ā»Bioblast linkĀ«]] | |||
:::# Beard DA (2005) A biophysical model of the mitochondrial respiratory system and oxidative phosphorylation. PLOS Comput Biol 1(4):e36. - [[Beard 2005 PLOS Comput Biol |Ā»Bioblast linkĀ«]] | |||
:::# Einstein A (1905) Ćber die von der molekularkinetischen Theorie der WƤrme geforderte Bewegung von in ruhenden FlĆ¼ssigkeiten suspendierten Teilchen. Ann Physik 4, XVII:549-60. - [[Einstein 1905 Ann Physik 549 |Ā»Bioblast linkĀ«]] | |||
:::# Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - [[Gnaiger_1993_Pure_Appl_Chem |Ā»Bioblast linkĀ«]] Ā | |||
:::# Gnaiger E (1989) Mitochondrial respiratory control: energetics, kinetics and efficiency. In: Energy transformations in cells and organisms. Wieser W, Gnaiger E (eds), Thieme, Stuttgart:6-17. - [[Gnaiger_1989_Energy_Transformations |Ā»Bioblast linkĀ«]] | |||
:::# Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5<sup>th</sup> ed. https://doi.org/10.26124/bec:2020-0002 - The symbols in the above abstract have been adjusted to those in the 5<sup>th</sup> ed. | |||
Ā | |||
{{Labeling | |||
|area=Respiration | |||
|topics=Flux control, Ion;substrate transport, mt-Membrane potential | |||
|couplingstates=LEAK | |||
|event=Oral | |||
|additional=MitoEAGLE | |||
}} |
Latest revision as of 22:17, 4 July 2022
The protonmotive force under pressure: an isomorphic analysis. |
Link: EBEC2018
Gnaiger E (2018)
Event: EBEC2018 Budapest HU
ā.. the sum of the electrical pressure difference and the osmotic pressure difference (i.e. the electrochemical potential difference) of protonsā [1] links to non-ohmic flux-force relationships between proton leak and protonmotive force pmF. This is experimentally established, has direct consequences on mitochondrial physiology, but is theoretically little understood [2,3]. Here I distinguish pressure from potential differences (diffusion: ĪĪ¼H+ or ĪdFH+; electric: ĪĪØ or ĪelFp+), to explain non-ohmic flux-force relationships on the basis of four thermodynamic theorems. (1) Einsteinās diffusion equation [4] explains the concentration gradient (dc/dz) in Fickās law as the product of chemical potential gradient (the vector force and resistance determine the velocity v of a particle) and local concentration c. This yields the chemical pressure gradient (vanāt Hoff): ddĪ /dz = RTādc/dz. Flux [5] is the product of v and c; c varies with force. Therefore, flux-force relationships are non-linear. (2) The pmF is not a vector force; the gradient is replaced by a pressure difference, and local concentration by a distribution function or free activity Ī±. Flux is a function of Ī± and force, Jd = -udāĪ±āĪdFX = -udāĪdĪ X [6]. (3) At ĪelFp+ = -ĪdFH+, the diffusion pressure of protons, ĪdĪ H+ = RTāĪcH+ [Pa=Jām-3] is balanced by electric pressure, maintained by counterions of H+. Diffusional and electric pressures are isomorphic, additive, and yield protonmotive pressure pmp. (4) The dependence of proton leak on pmF varies with ĪelFp+ versus ĪdFH+, in agreement with experimental evidence. The flux-force relationship is concave at high mitochondrial volume fractions, but near-exponential at small mt-matrix volume ratios. Linear flux-pmp relationships imply a near-exponential dependence of the proton leak on the pmF ([7]; added 2022-07-04).
ā¢ Bioblast editor: Gnaiger E
ā¢ O2k-Network Lab: AT Innsbruck Gnaiger E
Affiliations
- D. Swarovski Research Lab, Dept Visceral, Transplant Thoracic Surgery, Medical Univ Innsbruck
- Oroboros Instruments
- Innsbruck, Austria. - [email protected]
References
- Mitchell P (1966) Chemiosmotic coupling in oxidative and photosynthetic phosphorylation. Glynn Research, Bodmin. Biochim Biophys Acta Bioenergetics 1807:1507-38. - Ā»Bioblast linkĀ«
- Garlid KD, Beavis AD, Ratkje SK (1989) On the nature of ion leaks in energy-transducing membranes. Biochim Biophys Acta 976:109-20. - Ā»Bioblast linkĀ«
- Beard DA (2005) A biophysical model of the mitochondrial respiratory system and oxidative phosphorylation. PLOS Comput Biol 1(4):e36. - Ā»Bioblast linkĀ«
- Einstein A (1905) Ćber die von der molekularkinetischen Theorie der WƤrme geforderte Bewegung von in ruhenden FlĆ¼ssigkeiten suspendierten Teilchen. Ann Physik 4, XVII:549-60. - Ā»Bioblast linkĀ«
- Gnaiger E (1993) Nonequilibrium thermodynamics of energy transformations. Pure Appl Chem 65:1983-2002. - Ā»Bioblast linkĀ«
- Gnaiger E (1989) Mitochondrial respiratory control: energetics, kinetics and efficiency. In: Energy transformations in cells and organisms. Wieser W, Gnaiger E (eds), Thieme, Stuttgart:6-17. - Ā»Bioblast linkĀ«
- Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5th ed. https://doi.org/10.26124/bec:2020-0002 - The symbols in the above abstract have been adjusted to those in the 5th ed.
Labels: MiParea: Respiration
Regulation: Flux control, Ion;substrate transport, mt-Membrane potential
Coupling state: LEAK
Event: Oral
MitoEAGLE