Difference between revisions of "Flux control ratio"

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high-resolution terminology - matching measurements at high-resolution

Flux control ratio

Description

Flux control ratios (FCR), are ratios of oxygen flux in different respiratory control states, normalized for maximum flux in a common reference state, to obtain theoretical lower and upper limits of 0.0 and 1.0 (0% and 100%).

For a given protocol or set of respiratory protocols, flux control ratios provide a fingerprint of coupling and substrate control independent of (i) mt-content in cells or tissues, (ii) purification in preparations of isolated mitochondria, and (iii) assay conditions for determination of tissue mass or mt-markers external to a respiratory protocol (CS, protein, stereology, etc.). FCR obtained from a single respirometric incubation with sequential titrations (sequential protocol; SUIT protocol) provide an internal normalization, expressing respiratory control independent of mitochondrial content and thus independent of a marker for mitochondrial amount. FCR obtained from separate (parallel) protocols depend on equal distribution of subsamples obtained from a homogenous mt-preparation or determination of a common mitochondrial marker.

Abbreviation: FCR

Reference: Gnaiger 2014 MitoPathways, Gnaiger 2009 Int J Biochem Cell Biol, Doerrier 2018 Methods Mol Biol

Flux control factor: normalization of mitochondrial respiration

» More details: Flux control factor

DatLab

Unknown sample concentration and normalization per unit sample [x]

In the DatLab 7.4 Excel template for oxygen flux analysis (O2 analysis template DL7.4):

If the sample concentration is not yet known, the box ‘Known sample concentration’ can be unchecked, and the concentration will be considered by default as 1, with units [x·mL^-1]. In this way, flux can be normalized and FCRs can be obtained even if the sample concentration is unknown.

» Read also: Extensive quantity; BEC 2020.1

» More details: MiPNet24.06 Oxygen flux analysis - DatLab 7.4

FCR in DatLab plot

The entire plot of oxygen flux can be converted to a FCR. Click on 'Flux/Slope' in the DatLab pull-down menu. Select chamber A or B 'O2 slope'. Select 'Flux control ratio, FCR' and select the mark that corresponds to the reference state. Change the scale under 'Graph/Scaling' (or press F6).

» More details: Flux/Slope in DatLab

References

Bioblast link	Reference	Year
Doerrier 2018 Methods Mol Biol	Doerrier C, Garcia-Souza LF, Krumschnabel G, Wohlfarter Y, Mészáros AT, Gnaiger E (2018) High-Resolution FluoRespirometry and OXPHOS protocols for human cells, permeabilized fibers from small biopsies of muscle, and isolated mitochondria. Methods Mol Biol 1782:31-70. https://doi.org/10.1007/978-1-4939-7831-1_3	2018
Gnaiger 2009 Int J Biochem Cell Biol	Gnaiger E (2009) Capacity of oxidative phosphorylation in human skeletal muscle. New perspectives of mitochondrial physiology. Int J Biochem Cell Biol 41:1837-45. https://doi.org/10.1016/j.biocel.2009.03.013	2009
Gnaiger 2020 BEC MitoPathways	Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5^th ed. Bioenerg Commun 2020.2. https://doi.org/10.26124/bec:2020-0002	2020
BEC 2020.1 doi10.26124bec2020-0001.v1	Gnaiger E et al ― MitoEAGLE Task Group (2020) Mitochondrial physiology. Bioenerg Commun 2020.1. https://doi.org/10.26124/bec:2020-0001.v1	2020

Bioblast links: Normalization - >>>>>>> - Click on [Expand] or [Collapse] - >>>>>>>

Rate

» Normalization of rate

» Flow

» Oxygen flow

» Flux

» Oxygen flux

» Flux control ratio

» Coupling-control ratio

» Pathway control ratio

» Flux control efficiency

Quantities for normalization

» Count in contrast to Number

» Mitochondrial marker

» O2k-Protocols: mitochondrial and marker-enzymes

» Citrate synthase activity

General

» Extensive quantity

» Specific quantity

» Advancement

» Motive unit

» Iconic symbols

Related keyword lists

» Keywords: Concentration and pressure

MitoPedia concepts: Respiratory control ratio, SUIT concept

MitoPedia methods: Respirometry

MitoPedia O2k and high-resolution respirometry: DatLab

@@ Line 1: / Line 1: @@
 {{MitoPedia
-|abbr=FCR
+|abbr=''FCR''
-|description='''Flux control ratios''' express respiratory control independent of mitochondrial content and cell size. FCR are normalized for maximum flux in a common reference state, to obtain theoretical lower and upper limits of 0.0 and 1.0 (0% and 100%).
+|description='''Flux control ratios''' (''FCR''), are ratios of oxygen flux in different respiratory control states, normalized for maximum flux in a common reference state, to obtain theoretical lower and upper limits of 0.0 and 1.0 (0% and 100%).
-. ROX/E’: The ROX/E’ ratio is low (0.01 to 0.07; Tab. 1), but ROX contributes to a
+For a given protocol or set of respiratory protocols, flux control ratios provide a fingerprint of coupling and substrate control independent of (i) mt-content in cells or tissues, (ii) purification in preparations of isolated mitochondria, and (iii) assay conditions for determination of tissue mass or mt-markers external to a respiratory protocol (CS, protein, stereology, etc.). ''FCR'' obtained from a single respirometric incubation with sequential titrations (sequential protocol; [[SUIT|SUIT protocol]]) provide an internal normalization, expressing respiratory control independent of mitochondrial content and thus independent of a marker for mitochondrial amount. ''FCR'' obtained from separate (parallel) protocols depend on equal distribution of subsamples obtained from a homogenous mt-preparation or determination of a common [[mitochondrial marker]].
-significant extent to LEAK respiration, with corresponding ROX/L’ ratios ranging from
+|info=[[Gnaiger 2014 MitoPathways]], [[Gnaiger 2009 Int J Biochem Cell Biol]], [[Doerrier 2018 Methods Mol Biol]]
-.1 to 0.3, and up to 0.5 in growth-arrested fibroblasts (Tab. 1).
-. L/E: The LEAK control ratio is the ratio of LEAK respiration and ETS capacity. L/E
-ranges from 0.09 to 0.14 in various cells (Tab. 1; the inverse, 11 to 7, is the respiratory
-control ratio, RCR; ref. 1,11). Dyscoupling increases the L/E ratio, e.g. to 0.21 in
-senescent fibroblasts (Tab. 1). Alternatively, the L/E ratio may increase without intrinsic
-uncoupling or dyscoupling, if ETS capacity is diminished. It is, therefore, important to
-evaluate potential defects of ETS capacity per mt-marker, e.g. ETS per citrate synthase
-activity (5,8,11).
-. R/E: The ROUTINE control ratio is the ratio of (coupled) ROUTINE respiration and (noncoupled)
-ETS capacity. R/E ranges from 0.2 to 0.4 (Tab. 1; the inverse of 5 to 2.5 is the
-uncoupling control ratio, UCR; ref. 3-8). The R/E ratio is an expression of how close
-ROUTINE respiration operates to ETS capacity. Reported R/E ratios�0.5 (15) could not
-be reproduced by HRR in a wide range of human cell types and incubation conditions (Tab.
-). The discrepancies cannot be fully explained by high glucose concentrations in culture
-and respiration media, since glucose exerts an effect not only on R but also on E (13). R/E
-ratios increase due to (i) high ATP demand and ADP-stimulated ROUTINE respiration, (ii)
-dyscoupling (senescent fibroblasts; Tab. 1), and (iii) limitation of respiratory capacity by
-defects of substrate oxidation and complexes of the ETS.
-. (R-L)/E: The netROUTINE control ratio, (R-L)/E, expresses phosphorylation-related
-respiration (corrected for LEAK respiration) as a fraction of ETS capacity. 0.1 to 0.3 of
-ETS capacity is used for oxidative phosphorylation under ROUTINE conditions (Tab. 1).
-(R-L)/E remains constant, if dyscoupling is fully compensated by an increase of ROUTINE
-respiration and a constant rate of oxidative phosphorylation is maintained (fibroblasts in
-Tab. 1). Upon stimulation of OXPHOS by an increased ATP demand, or if the respiratory
-capacity declines without effect on the rate of OXPHOS, however, (R-L)/E increases,
-which indicates that a higher proportion of the maximum capacity is activated to drive
-ATP synthesis. (R-L)/E declines to zero in either fully uncoupled cells (R=L=E) or in cells
-under metabolic arrest (R=L<E).
-. If the PC protocol is extended by measurement of cytochrome c oxidase, then the ratio of
-CIV activity and non-coupled respiration is an index of the apparent excess capacity of this
-enzyme step in the ETS. Autooxidation of ascorbate and TMPD (Tab. 2) is extremely high
-in culture media, hence a mitochondrial respiration medium is used (5).
-|info=[[MiPNet12.15]]; [[Pesta_2010_Protocol]]
-|type=Respiration
 }}
-{{Labeling
-|topics=Respiration; OXPHOS; ETS Capacity, Flux Control; Additivity; Threshold; Excess Capacity
+== Flux control factor: normalization of mitochondrial respiration ==
+::::» ''More details:'' [[Flux control factor]]
+== DatLab ==
+=== Unknown sample concentration and normalization per unit sample [x] ===
+:::* In the DatLab 7.4 Excel template for oxygen flux analysis (O2 analysis template DL7.4):
+:::: If the sample concentration is not yet known, the box ‘Known sample concentration’ can be unchecked, and the concentration will be considered by default as 1, with units [x·mL<sup>-1</sup>]. In this way, flux can be normalized and ''FCR''s can be obtained even if the sample concentration is unknown.
+::::» ''Read also:'' [[Extensive quantity]]; [[BEC 2020.1 doi10.26124bec2020-0001.v1|BEC 2020.1]]
+::::» ''More details:'' [[MiPNet24.06 Oxygen flux analysis - DatLab 7.4]]
+=== ''FCR'' in DatLab plot ===
+:::* The entire plot of oxygen flux can be converted to a ''FCR''. Click on 'Flux/Slope' in the DatLab pull-down menu.  Select chamber A or B 'O2 slope'. Select 'Flux control ratio, FCR' and select the mark that corresponds to the reference state. Change the scale under 'Graph/Scaling' (or press F6).
+::::» ''More details:'' [[Flux_/_Slope#Slope_configuration_menu|Flux/Slope in DatLab]]
+== References ==
+{{#ask:[[Additional label::Flux control ratio]]
+| mainlabel=Bioblast link
+|?Has title=Reference
+|?Was published in year=Year
+|format=broadtable
+|limit=5000
+|offset=0
+|sort=Has title
+|order=ascending
+}}
+{{Template:Keywords: Normalization}}
+{{MitoPedia concepts
+|mitopedia concept=Respiratory control ratio, SUIT concept
+}}
+{{MitoPedia methods
+|mitopedia method=Respirometry
+}}
+{{MitoPedia O2k and high-resolution respirometry
+|mitopedia O2k and high-resolution respirometry=DatLab
 }}