Difference between revisions of "P-L net OXPHOS capacity"
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|description=[[Image:P-L.jpg|50 px| | |description=[[Image:P-L.jpg|50 px|P-L net OXPHOS capacity|''P-L'' net OXPHOS capacity]] The '''''P-L'' net OXPHOS capacity''' is the [[OXPHOS capacity]] corrected for [[LEAK respiration]]. ''P-L'' is the scope for ADP stimulation, the respiratory capacity potentially available for phosphorylation of ADP to ATP. Oxygen consumption in the OXPHOS state, therefore, is partitioned into ''P-L'', strictly coupled to phosphorylation ''P»'', and nonphosphorylating LEAK respiration, ''L<sub>P</sub>'', compensating for proton leaks, slip and cation cycling: ''P'' = ''P-L''+''L<sub>P</sub>''. It is frequently assumed that [[LEAK respiration]] ''L'' as measured in the LEAK state, overestimates the LEAK component of respiration, ''L<sub>P</sub>'', as measured in the OXPHOS state, particularly if the protonmotive force is not adjusted to equivalent levels in ''L'' and ''L<sub>P</sub>''. However, if the LEAK component increases with enzyme turnover during ''P'', the low enzyme turnover during ''L'' may counteract the effect of the higher ''pmF''. | ||
|info=[[Gnaiger | |info=[[Gnaiger 2020 BEC MitoPathways]] | ||
}} | }} | ||
Communicated by [[Gnaiger E]] (2014-08-09) last update 2020-11-11 | |||
Communicated by [[Gnaiger E]] 2014-08-09 | |||
== | == Keywords == | ||
:: | ::::* Expand Bioblast links to '''''P-L'' net OXPHOS capacity''' | ||
{{Template:Keywords: Coupling control}} | |||
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Latest revision as of 01:27, 31 December 2020
Description
The P-L net OXPHOS capacity is the OXPHOS capacity corrected for LEAK respiration. P-L is the scope for ADP stimulation, the respiratory capacity potentially available for phosphorylation of ADP to ATP. Oxygen consumption in the OXPHOS state, therefore, is partitioned into P-L, strictly coupled to phosphorylation P», and nonphosphorylating LEAK respiration, LP, compensating for proton leaks, slip and cation cycling: P = P-L+LP. It is frequently assumed that LEAK respiration L as measured in the LEAK state, overestimates the LEAK component of respiration, LP, as measured in the OXPHOS state, particularly if the protonmotive force is not adjusted to equivalent levels in L and LP. However, if the LEAK component increases with enzyme turnover during P, the low enzyme turnover during L may counteract the effect of the higher pmF.
Abbreviation: P-L
Reference: Gnaiger 2020 BEC MitoPathways
Communicated by Gnaiger E (2014-08-09) last update 2020-11-11
Keywords
- Expand Bioblast links to P-L net OXPHOS capacity
4-compartmental OXPHOS model. (1) ET capacity E of the noncoupled electron transfer system ETS. OXPHOS capacity P is partitioned into (2) the dissipative LEAK component L, and (3) ADP-stimulated P-L net OXPHOS capacity. (4) If P-L is kinetically limited by a low capacity of the phosphorylation system to utilize the protonmotive force pmF, then the apparent E-P excess capacity is available to drive coupled processes other than phosphorylation P» (ADP to ATP) without competing with P».
- Bioblast links: Coupling control - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>
1. Mitochondrial and cellular respiratory rates in coupling-control states
Respiratory rate | Defining relations | Icon | |
---|---|---|---|
OXPHOS capacity | P = P´-Rox | mt-preparations | |
ROUTINE respiration | R = R´-Rox | living cells | |
ET capacity | E = E´-Rox | » Level flow | |
» Noncoupled respiration - Uncoupler | |||
LEAK respiration | L = L´-Rox | » Static head | |
» LEAK state with ATP | |||
» LEAK state with oligomycin | |||
» LEAK state without adenylates | |||
Residual oxygen consumption Rox | L = L´-Rox |
2. Flux control ratios related to coupling in mt-preparations and living cells
FCR | Definition | Icon | |
---|---|---|---|
L/P coupling-control ratio | L/P | » Respiratory acceptor control ratio, RCR = P/L | |
L/R coupling-control ratio | L/R | ||
L/E coupling-control ratio | L/E | » Uncoupling-control ratio, UCR = E/L (ambiguous) | |
P/E control ratio | P/E | ||
R/E control ratio | R/E | » Uncoupling-control ratio, UCR = E/L | |
net P/E control ratio | (P-L)/E | ||
net R/E control ratio | (R-L)/E |
3. Net, excess, and reserve capacities of respiration
Respiratory net rate | Definition | Icon |
---|---|---|
P-L net OXPHOS capacity | P-L | |
R-L net ROUTINE capacity | R-L | |
E-L net ET capacity | E-L | |
E-P excess capacity | E-P | |
E-R reserve capacity | E-R |
4. Flux control efficiencies related to coupling-control ratios
Coupling-control efficiency | Definition | Icon | Canonical term | ||
---|---|---|---|---|---|
P-L control efficiency | jP-L | = (P-L)/P | = 1-L/P | P-L OXPHOS-flux control efficiency | |
R-L control efficiency | jR-L | = (R-L)/R | = 1-L/R | R-L ROUTINE-flux control efficiency | |
E-L coupling efficiency | jE-L | = (E-L)/E | = 1-L/E | E-L ET-coupling efficiency » Biochemical coupling efficiency | |
E-P control efficiency | jE-P | = (E-P)/E | = 1-P/E | E-P ET-excess flux control efficiency | |
E-R control efficiency | jE-R | = (E-R)/E | = 1-R/E | E-R ET-reserve flux control efficiency |
5. General
- » Basal respiration
- » Cell ergometry
- » Dyscoupled respiration
- » Dyscoupling
- » Electron leak
- » Electron-transfer-pathway state
- » Hyphenation
- » Oxidative phosphorylation
- » Oxygen flow
- » Oxygen flux
- » Permeabilized cells
- » Phosphorylation system
- » Proton leak
- » Proton slip
- » Respiratory state
- » Uncoupling