Flux control efficiency: Difference between revisions
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{{MitoPedia | {{MitoPedia | ||
|abbr=''j<sub>Z-Y</sub>'' | |abbr=''j<sub>Z-Y</sub>'' | ||
|description='''Flux control efficiencies''' express the control of respiration by a [[metabolic control variable]], ''X'', as a fractional change of flux from ''Y<sub>X</sub>'' to ''Z<sub>X</sub>'', normalized for ''Z<sub>X</sub>''. ''Z<sub>X</sub>'' is the [[reference state]] with high (stimulated or un-inhibited) flux; ''Y<sub>X</sub>'' is the [[background state]] at low flux, upon which ''X'' acts. | |description='''Flux-control efficiencies''' express the control of respiration by a [[metabolic control variable]], ''X'', as a fractional change of flux from ''Y<sub>X</sub>'' to ''Z<sub>X</sub>'', normalized for ''Z<sub>X</sub>''. ''Z<sub>X</sub>'' is the [[reference state]] with high (stimulated or un-inhibited) flux; ''Y<sub>X</sub>'' is the [[background state]] at low flux, upon which ''X'' acts. | ||
:: ''j<sub>Z-Y</sub>'' = (''Z<sub>X</sub>-Y<sub>X</sub>'')/''Z<sub>X</sub>'' = 1-''Y<sub>X</sub>''/''Z<sub>X</sub>'' | :: ''j<sub>Z-Y</sub>'' = (''Z<sub>X</sub>-Y<sub>X</sub>'')/''Z<sub>X</sub>'' = 1-''Y<sub>X</sub>''/''Z<sub>X</sub>'' | ||
Complementary to the concept of [[flux control ratio]]s and analogous to [[elasticity|elasticities]] of [[metabolic control analysis]], the flux control efficiency of ''X'' upon background ''Y<sub>X</sub>'' is expressed as the change of flux from ''Y<sub>X</sub>'' to ''Z<sub>X</sub>'' normalized for the reference state ''Z<sub>X</sub>''. | Complementary to the concept of [[flux-control ratio]]s and analogous to [[elasticity|elasticities]] of [[metabolic control analysis]], the flux-control efficiency of ''X'' upon background ''Y<sub>X</sub>'' is expressed as the change of flux from ''Y<sub>X</sub>'' to ''Z<sub>X</sub>'' normalized for the reference state ''Z<sub>X</sub>''. | ||
ยป [[Flux_control_efficiency#Flux_control_efficiency:_normalization_of_mitochondrial_respiration | '''MiPNet article''']] | ยป [[Flux_control_efficiency#Flux_control_efficiency:_normalization_of_mitochondrial_respiration | '''MiPNet article''']] | ||
|info=[[Gnaiger 2020 MitoPathways]] | |info=[[Gnaiger 2020 MitoPathways]] | ||
}} | }} | ||
__TOC__ | __TOC__ | ||
= Flux control efficiency: normalization of mitochondrial respiration = | = Flux-control efficiency: normalization of mitochondrial respiration = | ||
{{Publication | {{Publication | ||
|title=Gnaiger E (2020) Flux control efficiency: normalization of mitochondrial respiration. Mitochondr Physiol Network 2016-03-20; updated 2020-11-10. | |title=Gnaiger E (2020) Flux-control efficiency: normalization of mitochondrial respiration. Mitochondr Physiol Network 2016-03-20; updated 2020-11-10. | ||
|info=[[Gnaiger 2020 MitoPathways]] | |info=[[Gnaiger 2020 MitoPathways]] | ||
|authors=Oroboros | |authors=Oroboros | ||
|year=2020 | |year=2020 | ||
|journal=MiPNet | |journal=MiPNet | ||
|abstract=The [[flux control efficiency]], ''j<sub>Z-Y</sub>'', and [[flux control ratio]], ''FCR'', are internal normalizations, expressing respiratory flux in a given state relative to respiratory flux in a reference state. Whereas ''FCR''s express various respiratory states relative to a common refrence state, ''j<sub>Z-Y</sub>'' express the control of respiration in a single ''step'' caused by a specific metabolic control variable ''X''. The concept of the flux control efficiency presents a generalized framework for assessing the effect of an experimental variable on flux and defines specific expressions, such as the biochemical coupling efficiency. | |abstract=The [[flux-control efficiency]], ''j<sub>Z-Y</sub>'', and [[flux-control ratio]], ''FCR'', are internal normalizations, expressing respiratory flux in a given state relative to respiratory flux in a reference state. Whereas ''FCR''s express various respiratory states relative to a common refrence state, ''j<sub>Z-Y</sub>'' express the control of respiration in a single ''step'' caused by a specific metabolic control variable ''X''. The concept of the flux control efficiency presents a generalized framework for assessing the effect of an experimental variable on flux and defines specific expressions, such as the biochemical coupling efficiency. | ||
|mipnetlab=AT Innsbruck Gnaiger E | |mipnetlab=AT Innsbruck Gnaiger E | ||
}} | }} | ||
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:::: If inhibitors are experimentally added rather than removed (-''X''); then ''Y<sub>X</sub>'' is the background rate in the presence of the inhibitor. | :::: If inhibitors are experimentally added rather than removed (-''X''); then ''Y<sub>X</sub>'' is the background rate in the presence of the inhibitor. | ||
::::* ''X'': '''Metabolic control variable''' acting on ''Y<sub>X</sub>'' in the [[background state]], to yield rate ''Z<sub>X</sub>'' in the [[reference state]]. ''X'' stimulates or un-inhibits ''Y<sub>X</sub>'' from low flux to ''Z<sub>X</sub>'' at high flux. | ::::* ''X'': '''Metabolic control variable''' acting on ''Y<sub>X</sub>'' in the [[background state]], to yield rate ''Z<sub>X</sub>'' in the [[reference state]]. ''X'' stimulates or un-inhibits ''Y<sub>X</sub>'' from low flux to ''Z<sub>X</sub>'' at high flux. | ||
::::* ''Y<sub>X</sub>'': The rate in the '''background state''' Y is the non-activated or inhibited respiratory rate (low) in relation to the high rate ''Z<sub>X</sub>'' in the [[reference state]] Z. A [[metabolic control variable]], ''X'', acts on ''Y<sub>X</sub>'' (substrate, activator) or is removed from Y (inhibitor) to yield ''Z<sub>X</sub>''. The ''X''-specific (in contrast to general) [[flux control ratio]] is ''Y/Z''. | ::::* ''Y<sub>X</sub>'': The rate in the '''background state''' Y is the non-activated or inhibited respiratory rate (low) in relation to the high rate ''Z<sub>X</sub>'' in the [[reference state]] Z. A [[metabolic control variable]], ''X'', acts on ''Y<sub>X</sub>'' (substrate, activator) or is removed from Y (inhibitor) to yield ''Z<sub>X</sub>''. The ''X''-specific (in contrast to general) [[flux-control ratio]] is ''Y/Z''. | ||
::::* ''Z<sub>X</sub>'': The rate in the '''reference state''' Z, stimulated or un-inhibited by a [[metabolic control variable]], ''X'', with high rate in relation to rate ''Y<sub>X</sub>'' in the [[background state]] Y. | ::::* ''Z<sub>X</sub>'': The rate in the '''reference state''' Z, stimulated or un-inhibited by a [[metabolic control variable]], ''X'', with high rate in relation to rate ''Y<sub>X</sub>'' in the [[background state]] Y. | ||
Revision as of 22:29, 10 November 2020
Description
Flux-control efficiencies express the control of respiration by a metabolic control variable, X, as a fractional change of flux from YX to ZX, normalized for ZX. ZX is the reference state with high (stimulated or un-inhibited) flux; YX is the background state at low flux, upon which X acts.
- jZ-Y = (ZX-YX)/ZX = 1-YX/ZX
Complementary to the concept of flux-control ratios and analogous to elasticities of metabolic control analysis, the flux-control efficiency of X upon background YX is expressed as the change of flux from YX to ZX normalized for the reference state ZX. ยป MiPNet article
Abbreviation: jZ-Y
Reference: Gnaiger 2020 MitoPathways
Flux-control efficiency: normalization of mitochondrial respiration
Gnaiger E (2020) Flux-control efficiency: normalization of mitochondrial respiration. Mitochondr Physiol Network 2016-03-20; updated 2020-11-10. |
Abstract: The flux-control efficiency, jZ-Y, and flux-control ratio, FCR, are internal normalizations, expressing respiratory flux in a given state relative to respiratory flux in a reference state. Whereas FCRs express various respiratory states relative to a common refrence state, jZ-Y express the control of respiration in a single step caused by a specific metabolic control variable X. The concept of the flux control efficiency presents a generalized framework for assessing the effect of an experimental variable on flux and defines specific expressions, such as the biochemical coupling efficiency.
โข O2k-Network Lab: AT Innsbruck Gnaiger E
Metabolic control variable and respiratory state
- A metabolic control variable X is either added (stimulation, activation) or removed (reversal of inhibition) to yield a high flux Z in the reference state, compared to flux Y in the background state. X denotes the metabolic control variable; Y and Z are the respiratory states, whereas Y and Z denote the corresponding respiratory fluxes. jZ-Y in step analysis relates to the change of flux caused by the variable X. The FCR in state analysis compares fluxes in a variety of respiratory states which may be separated by single or multiple variables, i.e. separated by several coupling and [[pathway control state]s.
- If inhibitors are experimentally added rather than removed (-X); then YX is the background rate in the presence of the inhibitor.
- X: Metabolic control variable acting on YX in the background state, to yield rate ZX in the reference state. X stimulates or un-inhibits YX from low flux to ZX at high flux.
- YX: The rate in the background state Y is the non-activated or inhibited respiratory rate (low) in relation to the high rate ZX in the reference state Z. A metabolic control variable, X, acts on YX (substrate, activator) or is removed from Y (inhibitor) to yield ZX. The X-specific (in contrast to general) flux-control ratio is Y/Z.
- ZX: The rate in the reference state Z, stimulated or un-inhibited by a metabolic control variable, X, with high rate in relation to rate YX in the background state Y.
- If inhibitors are experimentally added rather than removed (-X); then YX is the background rate in the presence of the inhibitor.
Pathway control efficiency
- Pathway control efficiencies express the relative change of oxygen flux in response to a transition of (1) CHNO-fuel substrates or (2) inhibitors of enzyme steps in the pathway, in a defined coupling state.
- ยป NS-N pathway control efficiency, NS-S pathway control efficiency
Coupling control efficiency
- Coupling control efficiencies are determined in an ET-pathway competent state. The terms coupling efficiency and coupling control efficiency are used synonymously.
mt-Preparations
- In mitochondrial preparations, there are three well-defined coupling states of respiration, L, P, E (LEAK, OXPHOS, Electron transfer pathway).
- 1. If the metabolic control variable, X, is an uncoupler, the reference rate ZX is E. Then two background states Y, of coupling control are possible: The uncoupler may act on the L or P state in mt-preparations. The corresponding coupling control efficiencies are:
- ET-coupling efficiency E-L, jE-L = (E-L)/E = 1-L/E (E-L coupling control efficiency).
- ET-excess control efficiency E-P, jE-P = (E-P)/E = 1-P/E (E-P control efficiency).
- 1. If the metabolic control variable, X, is an uncoupler, the reference rate ZX is E. Then two background states Y, of coupling control are possible: The uncoupler may act on the L or P state in mt-preparations. The corresponding coupling control efficiencies are:
- 2. If the metabolic control variable is stimulation by ADP, D, or release of an inhibitor of phosphorylation of ADP to ATP (DT-phosphorylation; e.g. -Omy), the reference state Z is P at saturating concentrations of ADP. The background state Y is L, and the corresponding coupling control efficiency is:
- OXPHOS-coupling efficiency, jP-L = (P-L)/P = 1-L/P (P-L coupling control efficiency), related to the RCR.
- 2. If the metabolic control variable is stimulation by ADP, D, or release of an inhibitor of phosphorylation of ADP to ATP (DT-phosphorylation; e.g. -Omy), the reference state Z is P at saturating concentrations of ADP. The background state Y is L, and the corresponding coupling control efficiency is:
- 3. If the background state Y is L, the metablic control variable from L to P is ADP saturated ATP turnover or release of an inhibitor of phosphorylation of ADP to ATP, and the reference rate Z is E, the coupling control efficiency is complex (compare 1 and 2):
- (P-L)/E (net OXPHOS-control ratio).
- 3. If the background state Y is L, the metablic control variable from L to P is ADP saturated ATP turnover or release of an inhibitor of phosphorylation of ADP to ATP, and the reference rate Z is E, the coupling control efficiency is complex (compare 1 and 2):
Living cells
- L(Omy) and E can be induced in living cells, but state P cannot. However, the ROUTINE state of respiration, R, can be measured in living cells.
- 1. If the metabolic control variable, X, is an uncoupler, the reference rate Z is E. Then two background states, Y of coupling control are possible: The uncoupler may act on the LEAK or ROUTINE state in living cells. The corresponding coupling control efficiencies are:
- ET-coupling efficiency E-L, jE-L = (E-L)/E = 1-L/E (E-L coupling efficiency).
- ET-reserve control efficiency E-R, jE-R = (E-R)/E = 1-R/E.
- 1. If the metabolic control variable, X, is an uncoupler, the reference rate Z is E. Then two background states, Y of coupling control are possible: The uncoupler may act on the LEAK or ROUTINE state in living cells. The corresponding coupling control efficiencies are:
- 2. If the metabolic control variable is stimulation by ATP turnover or release of an inhibitor of phosphorylation of ADP to ATP (DT-phosphorylation; e.g. -Omy), the reference rate Z is R in living cells at physiologically controlled steady states of [ADP] and ATP-turnover. The background rate Y is L, and the corresponding coupling control efficiency is:
- ROUTINE-coupling efficiency R-L, jR-L = (R-L)/R = 1-L/R (R-L coupling efficiency).
- 2. If the metabolic control variable is stimulation by ATP turnover or release of an inhibitor of phosphorylation of ADP to ATP (DT-phosphorylation; e.g. -Omy), the reference rate Z is R in living cells at physiologically controlled steady states of [ADP] and ATP-turnover. The background rate Y is L, and the corresponding coupling control efficiency is:
- 3. If the background rate Y is L, the metablic control variable from L to R is cell-controlled ATP turnover or release of an inhibitor of phosphorylation of ADP to ATP, and the reference rate Z is E, the coupling control efficiency is complex (compare 1 and 2):
- (R-L)/E (net R/E control ratio).
- 3. If the background rate Y is L, the metablic control variable from L to R is cell-controlled ATP turnover or release of an inhibitor of phosphorylation of ADP to ATP, and the reference rate Z is E, the coupling control efficiency is complex (compare 1 and 2):
References
- Bioblast links: Normalization - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>
- Rate
- ยป Normalization of rate
- ยป Flow
- ยป Oxygen flow
- ยป Flux
- ยป Oxygen flux
- ยป Flux control ratio
- ยป Coupling-control ratio
- ยป Pathway control ratio
- ยป Flux control efficiency
- Rate
- Quantities for normalization
- ยป Count in contrast to Number
- ยป Mitochondrial marker
- ยป O2k-Protocols: mitochondrial and marker-enzymes
- ยป Citrate synthase activity
- Quantities for normalization
- General
- ยป Extensive quantity
- ยป Specific quantity
- ยป Advancement
- ยป Motive unit
- ยป Iconic symbols
- General
- Related keyword lists
MitoPedia concepts:
MiP concept,
Respiratory control ratio,
SUIT concept
MitoPedia methods:
Respirometry
Labels: MiParea: Respiration
Regulation: Flux control
HRR: Theory