Difference between revisions of "P-L net OXPHOS capacity"

Revision as of 19:01, 19 January 2015

high-resolution terminology - matching measurements at high-resolution

P-L net OXPHOS capacity

Description

The free OXPHOS capacity, ≈P, is the OXPHOS capacity corrected for LEAK respiration, ≈P = P-L. ≈P 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 the free OXPHOS capacity, ≈P, strictly coupled to phosphorylation, ~P, and nonphosphorylating LEAK respiration, L_P, compensating for proton leaks, slip and cation cycling: P = ≈P+L_P. It is frequently assumed that LEAK respiration, L, as measured in the LEAK state, overestimates the LEAK component of respiration, L_P, as measured in the OXPHOS state, particularly if the protonmotive force is not adjusted to equivalent levels in L and L_P. However, if the LEAK component increases with enzyme turnover during P, the low enzyme turnover during L may counteract the effect of the higher Δp_mt.

Abbreviation: ≈P

Reference: Gnaiger 2014 MitoPathways

MitoPedia methods: Respirometry

MitoPedia topics: "Respiratory state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property. Respiratory state"Respiratory state" is not in the list (Enzyme, Medium, Inhibitor, Substrate and metabolite, Uncoupler, Sample preparation, Permeabilization agent, EAGLE, MitoGlobal Organizations, MitoGlobal Centres, ...) of allowed values for the "MitoPedia topic" property.

The Blue Book 2014: Fig. 2.4.

Coupling control states for ≈P

» Respiratory state

Reference state, Z_X: OXPHOS capacity, P = P´-ROX
Background state, Y_X: LEAK respiration, L = L´-ROX
Metabolic control variable, X=Z_X-Y_X: Scope of ADP stimulation, free OXPHOS capacity, ≈P = P-L

Flux control factor

» Flux control factor, FCF

Coupling control factor, 1-Y_X/Z_X: P-L coupling control factor, OXPHOS coupling efficiency: j_≈P = ≈P/P =(P-L)/P = 1-L/P

Compare

Free ETS capacity, ≈E = E-L

netOXPHOS control ratio, ≈P/E control ratio: ≈P/E = (P-L)/E

ETS coupling efficiency, E-L control factor: j_≈E = ≈E/E = (E-L)/E = 1-L/E

Intact cells: Free ROUTINE activity, ≈R = R-L

@@ Line 1: / Line 1: @@
 {{MitoPedia
 |abbr=''≈P''
-|description=[[Image:P-L.jpg|50 px|Free OXPHOS capacity]] The '''free OXPHOS capacity''', ''≈P'', is the [[OXPHOS capacity]] corrected for [[LEAK respiration]], ''≈P'' = ''P-L''. ''≈P'' is the respiratory capacity potentially available for phosphorylation of ADP to ATP. Oxygen consumption in the OXPHOS state, therefore, is partitioned into the free OXPHOS capacity, ''≈P'', strictly coupled to phosphorylation, ''~P'', and nonphosphorylating LEAK respiration, ''L<sub>P</sub>'', compensating for proton leaks, slip and cation cycling: ''P'' = ''≈P''+''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 Δ''p''<sub>mt</sub>.
+|description=[[Image:P-L.jpg|50 px|Free OXPHOS capacity]] The '''free OXPHOS capacity''', ''≈P'', is the [[OXPHOS capacity]] corrected for [[LEAK respiration]], ''≈P'' = ''P-L''. ''≈P'' 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 the free OXPHOS capacity, ''≈P'', strictly coupled to phosphorylation, ''~P'', and nonphosphorylating LEAK respiration, ''L<sub>P</sub>'', compensating for proton leaks, slip and cation cycling: ''P'' = ''≈P''+''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 Δ''p''<sub>mt</sub>.
 |info=[[Gnaiger 2014 MitoPathways]]
 }}
@@ Line 11: / Line 11: @@
 }}
 [[File:EPL-free and excess.jpg|right|240px|thumb|[[Gnaiger 2014 MitoPathways |The Blue Book 2014]]: Fig. 2.4.]]
+== Coupling control states for ''≈P'' ==
+::» [[Respiratory state]]
+* [[Reference state]], ''Z<sub>X</sub>'': [[Image:P.jpg|link=OXPHOS capacity|OXPHOS]] [[OXPHOS capacity]], ''P'' = ''P´''-ROX
+* [[Background state]], ''Y<sub>X</sub>'': [[Image:L.jpg|link=LEAK respiration|LEAK]] [[LEAK respiration]], ''L'' = ''L´''-ROX
+* [[Metabolic control variable]], ''X=Z<sub>X</sub>-Y<sub>X</sub>'': [[Image:P-L.jpg|50 px|link=Free OXPHOS capacity |Free OXPHOS capacity]] Scope of ADP stimulation, [[free OXPHOS capacity]], ''≈P'' = ''P-L''
+== Flux control factor ==
+::» [[Flux control factor]], ''FCF''
+* [[Coupling control factor]], 1-''Y<sub>X</sub>/Z<sub>X</sub>'': [[Image:j--R.jpg|50 px|link=OXPHOS coupling efficiency |OXPHOS coupling efficiency]] ''P-L'' coupling control factor, [[OXPHOS coupling efficiency]]: ''j<sub>≈P</sub>'' = ''≈P/P'' =(''P-L'')/''P'' = 1-''L/P''
 == Compare ==
-* [[Free ROUTINE activity]] (intact cells)
+:: [[Image:E-L.jpg|50 px|link=Free ETS capacity |Free ETS capacity]] [[Free ETS capacity]], ''≈E'' = ''E-L''
-* [[Free ETS capacity]]
+:: [[Image:NetP over E.jpg|60 px|link=NetOXPHOS control ratio |netOXPHOS control ratio]] [[netOXPHOS control ratio]], ''≈P/E'' control ratio: ''≈P/E'' = (''P-L'')/''E''
+:: [[Image:j--E.jpg|50 px|link=ETS coupling efficiency |ETS coupling efficiency]] [[ETS coupling efficiency]], ''E-L'' control factor: ''j<sub>≈E</sub>'' = ''≈E/E'' = (''E-L'')/''E'' = 1-''L/E''
+* Intact cells: [[Image:R-L.jpg|50 px|link=Free ROUTINE activity |Free ROUTINE activity]] [[Free ROUTINE activity]], ''≈R'' = ''R-L''