Difference between revisions of "Succinate pathway"
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|description=[[File:SUIT-catg_S.jpg|right|300px|Succinate]] | |description=[[File:SUIT-catg_S.jpg|right|300px|Succinate]] | ||
'''S-pathway control''', S, is achieved with [[succinate]] as the single substrate, an [[Categories_of_SUIT_protocols#SUIT-Catg:_single_substrate_type |ETS-level 3 substrate]]: succinate-induced respiratory state; CII-linked; SRot; [[succinate alone]]. S supports electron flux through [[Complex II]] to CII-bound flavin adenine dinucleotide (FADH2) to [[Q]]. Inhibition of Complex I by '''[[rotenone]]''' (Rot; or amytal, piericidine) prevents accumulation of [[oxaloacetate]] which is a potent inhibitor of [[succinate dehydrogenase]]. After inhibition of CI by [[rotenone]], the NADH-linked dehydrogenases become inhibited by the redox shift from NAD<sup>+</sup> to NADH. Succinate dehydrogenase is activated by succinate and ATP, which explains in part the time-dependent increase of respiration in isolated mitochondria after addition of rotenone (first), succinate and ADP. | The '''S-pathway control state''', S, is achieved with [[succinate]] as the single substrate, an [[Categories_of_SUIT_protocols#SUIT-Catg:_single_substrate_type |ETS-level 3 substrate]]: succinate-induced respiratory state; CII-linked; SRot; [[succinate alone]]. S supports electron flux through [[Complex II]] to CII-bound flavin adenine dinucleotide (FADH2) to [[Q]]. Inhibition of Complex I by '''[[rotenone]]''' (Rot; or amytal, piericidine) prevents accumulation of [[oxaloacetate]] which is a potent inhibitor of [[succinate dehydrogenase]]. After inhibition of CI by [[rotenone]], the NADH-linked dehydrogenases become inhibited by the redox shift from NAD<sup>+</sup> to NADH. Succinate dehydrogenase is activated by succinate and ATP, which explains in part the time-dependent increase of respiration in isolated mitochondria after addition of rotenone (first), succinate and ADP. | ||
The '''Complex II-linked substrate state''' is induced in mt-preparations by addition of [[succinate]]&[[rotenone]] (Complex I inhibitor). Succinate is the direct substrate of [[Complex II]] (succinate dehydrogenase). In CII-linked respiration, only Complex III and Complex IV are involved in pumping protons from the matrix (P-phase) to the N-phase with a ~P/O ratio of 1.75 (P/O<sub>2</sub> = 3.5). | The '''Complex II-linked substrate state''' is induced in mt-preparations by addition of [[succinate]]&[[rotenone]] (Complex I inhibitor). Succinate is the direct substrate of [[Complex II]] (succinate dehydrogenase). In CII-linked respiration, only Complex III and Complex IV are involved in pumping protons from the matrix (P-phase) to the N-phase with a ~P/O ratio of 1.75 (P/O<sub>2</sub> = 3.5). |
Revision as of 19:47, 7 November 2016
Description
The S-pathway control state, S, is achieved with succinate as the single substrate, an ETS-level 3 substrate: succinate-induced respiratory state; CII-linked; SRot; succinate alone. S supports electron flux through Complex II to CII-bound flavin adenine dinucleotide (FADH2) to Q. Inhibition of Complex I by rotenone (Rot; or amytal, piericidine) prevents accumulation of oxaloacetate which is a potent inhibitor of succinate dehydrogenase. After inhibition of CI by rotenone, the NADH-linked dehydrogenases become inhibited by the redox shift from NAD+ to NADH. Succinate dehydrogenase is activated by succinate and ATP, which explains in part the time-dependent increase of respiration in isolated mitochondria after addition of rotenone (first), succinate and ADP.
The Complex II-linked substrate state is induced in mt-preparations by addition of succinate&rotenone (Complex I inhibitor). Succinate is the direct substrate of Complex II (succinate dehydrogenase). In CII-linked respiration, only Complex III and Complex IV are involved in pumping protons from the matrix (P-phase) to the N-phase with a ~P/O ratio of 1.75 (P/O2 = 3.5).
Abbreviation: S
Reference: Gnaiger 2014 MitoPathways - Chapter 4.1, Gnaiger 2000 Proc Natl Acad Sci U S A
MitoPedia concepts:
Respiratory state,
SUIT state
SRot(L)
- ~P/O2 ratio: Gnaiger 2000 Proc Natl Acad Sci U S A
- O2k-Protocols: MiPNet12.11 MitoRespiration
- Comparison with S alone, CI&II, and H2O2 production: Makrecka-Kuka 2015 Biomolecules
SRot(P)
- ~P/O2 ratio: Gnaiger 2000 Proc Natl Acad Sci U S A
- O2k-Protocols: MiPNet12.11 MitoRespiration
- Comparison with S alone CI&II, and H2O2 production: Makrecka-Kuka 2015 Biomolecules
SRot(E)
- O2k-Protocols: MiPNet12.11 MitoRespiration
- Comparison with CI-CI&II-CII SUIT protocol: Votion 2012 PLoS One
- SUIT_RP1: SUIT_FNSGp(PGM)01_7Rot: 1PM 2D&Dc (&DcNADH) 3U 4Oct 5G 6S 7Rot 8Gp 9Ama 10Tm 11Azd
List of publications: S- or CII-linked pathway control
- This list does not distinguish between substrate states for Succinate alone (without Rot) and SRot.