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Difference between revisions of "State 2"

From Bioblast
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{{MitoPedia
{{MitoPedia
|abbr=ROX<sub>D</sub>
|abbr=ROX<sub>D</sub>
|description=Substrate limited state of [[residual oxygen consumption]], after addition of ADP to isolated mitochondria suspended in mitochondrial respiration medium in the absence of reduced substrates (ROX<sub>D</sub>).Β  Residual endogenous substrates are oxidized during a transient stimulation of oxygen flux by ADP; ADP concentration (D) remains high during ROX<sub>D</sub>.
|description=Substrate limited state of [[residual oxygen consumption]], after addition of ADP to isolated mitochondria suspended in mitochondrial respiration medium in the absence of reduced substrates (ROX<sub>D</sub>).Β  Residual endogenous substrates are oxidized during a transient stimulation of oxygen flux by ADP. Subsequently oxygen flux declines to a low level (or zero) at the steady '''State 2''' ([[Chance_1955_JBC-III|Chance and Williams 1955]]). ADP concentration (D) remains high during ROX<sub>D</sub>.
Β 
In contrast to the definition of '''State 2''' by Chance and Williams (1955, 1956), a respiratory [[LEAK]] state may be induced as the second respiratory state in a protocol with isolated mitochondria, permeabilized tissues, or permeabilized cells, adding the mitochondrial preparation to respiration medium containing inorganic phosphate (State 1), then adding reduced substrate (no external adenylates, State 2'; whereas State 2 is defined as high [ADP] without external substrates). This second state is a non-phosphorylating LEAK state, ''L''<sub>N</sub> (N for no adenylates), when substrate-saturated respiration compensates for the proton leak (mainly) in the absence of ADP.
|info=[[MiPNet12.15]], [[Chance 1955 JBC-III]]
|info=[[MiPNet12.15]], [[Chance 1955 JBC-III]]
|type=Respiration
|type=Respiration
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{{Labeling
{{Labeling
|discipline=Mitochondrial Physiology
|discipline=Mitochondrial Physiology
|preparations=Isolated Mitochondria, Permeabilized Cell or Tissue; Homogenate
|kinetics=ADP; Pi, Reduced Substrate; Cytochrome c
|kinetics=ADP; Pi, Reduced Substrate; Cytochrome c
|topics=Respiratory state, Respiration; OXPHOS; ETS Capacity
|topics=Respiratory state, Respiration; OXPHOS; ETS Capacity
|type=Respiration
|type=Respiration
}}
}}
==An alternative protocol==
In contrast to the definition of State 2 by Chance and Williams (1955, 1956), a respiratory [[LEAK]] state may be induced as the second respiratory state in a protocol with isolated mitochondria, permeabilized tissues, or permeabilized cells, adding the mitochondrial preparation to respiration medium containing inorganic phosphate ([[State 1]]), then adding reduced substrate (no external adenylates). This second state (Estabrook 1967) is a non-phosphorylating LEAK state, ''L''<sub>N</sub> (N for no adenylates; Gnaiger 2009), when substrate-saturated respiration compensates for the proton leak (mainly) in the absence of ADP. State 2 (Chance and Williams 1955), however, is defined as high [ADP] without external substrates, followed by [[State 3]] induced by addition of reduced substrate(s).
==References==
Chance B, Williams GR (1955) Respiratory enzymes in oxidative phosphorylation. III. The steady state. J. Biol. Chem. 217: 409-427.
Chance B, Williams GR (1956) The respiratory chain and oxidative phosphorylation. Adv. Enzymol. 17: 65-134.
Estabrook R (1967) Mitochondrial respiratory control and the polarographic measurement of ADP:O ratios. Methods Enzymol. 10: 41-47.
Gnaiger E (2009) Capacity of oxidative phosphorylation in human skeletal muscle. New perspectives of mitochondrial physiology. Int. J. Biochem. Cell Biol. 41: 1837–1845. PMID: 19467914

Revision as of 07:02, 25 February 2011


high-resolution terminology - matching measurements at high-resolution


State 2

Description

Substrate limited state of residual oxygen consumption, after addition of ADP to isolated mitochondria suspended in mitochondrial respiration medium in the absence of reduced substrates (ROXD). Residual endogenous substrates are oxidized during a transient stimulation of oxygen flux by ADP. Subsequently oxygen flux declines to a low level (or zero) at the steady State 2 (Chance and Williams 1955). ADP concentration (D) remains high during ROXD.

Abbreviation: ROXD

Reference: MiPNet12.15, Chance 1955 JBC-III


Labels:



Preparation: Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property., Permeabilized Cell or Tissue; Homogenate"Permeabilized Cell or Tissue; Homogenate" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property. 

Regulation: Respiratory state"Respiratory state" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property., Respiration; OXPHOS; ETS Capacity"Respiration; OXPHOS; ETS Capacity" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property. 




An alternative protocol

In contrast to the definition of State 2 by Chance and Williams (1955, 1956), a respiratory LEAK state may be induced as the second respiratory state in a protocol with isolated mitochondria, permeabilized tissues, or permeabilized cells, adding the mitochondrial preparation to respiration medium containing inorganic phosphate (State 1), then adding reduced substrate (no external adenylates). This second state (Estabrook 1967) is a non-phosphorylating LEAK state, LN (N for no adenylates; Gnaiger 2009), when substrate-saturated respiration compensates for the proton leak (mainly) in the absence of ADP. State 2 (Chance and Williams 1955), however, is defined as high [ADP] without external substrates, followed by State 3 induced by addition of reduced substrate(s).

References

Chance B, Williams GR (1955) Respiratory enzymes in oxidative phosphorylation. III. The steady state. J. Biol. Chem. 217: 409-427.

Chance B, Williams GR (1956) The respiratory chain and oxidative phosphorylation. Adv. Enzymol. 17: 65-134.

Estabrook R (1967) Mitochondrial respiratory control and the polarographic measurement of ADP:O ratios. Methods Enzymol. 10: 41-47.

Gnaiger E (2009) Capacity of oxidative phosphorylation in human skeletal muscle. New perspectives of mitochondrial physiology. Int. J. Biochem. Cell Biol. 41: 1837–1845. PMID: 19467914