Difference between revisions of "Malate-anaplerotic pathway control state"
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|abbr=M | |abbr=M | ||
|description='''M''': [[Malate]] alone does not support respiration of mt-preparations if [[oxaloacetate]] cannot be metabolized further in the absence of a source of acetyl-CoA. Transport of oxaloacetate across the inner mt-membrane is restricted particularly in liver. Mitochondrial citrate and 2-oxoglutarate (Ξ±-ketoglutarate) are depleted by antiport with malate. [[Succinate]] is lost from the mitochondria through the dicarboxylate carrier. | |description=[[File:M.jpg|left|200px|M]] '''M''': [[Malate]] alone does not support respiration of mt-preparations if [[oxaloacetate]] cannot be metabolized further in the absence of a source of acetyl-CoA. Transport of oxaloacetate across the inner mt-membrane is restricted particularly in liver. Mitochondrial citrate and 2-oxoglutarate (Ξ±-ketoglutarate) are depleted by antiport with malate. [[Succinate]] is lost from the mitochondria through the dicarboxylate carrier. OXPHOS capacity with malate alone is only 1.3% of that with [[PM |Pyruvate&Malate]] in isolated rat skeletal muscle mitochondria. However, many mammalian and non-mammalian mitochondria have a mt-isoform of NADP<sup>+-</sup> or NAD(P)<big>+</big>-dependent [[malic enzyme]] (mtME), the latter being particularly active in proliferating cells. Then the [[anaplerotic pathway control state]] with malate alone (aN) supports high respiratory activities comparable to the NADH-linked pathway control states (N) with pyruvate&malate or glutamate&malate substrate combinations ([[PM-pathway control state]], [[GM-pathway control state]]). | ||
|info=Gnaiger | |info=[[Gnaiger 2020 BEC MitoPathways]] | ||
}} | }} | ||
Communicated by [[Gnaiger E]] 2016-01-24, edited by [[Cardoso LHD]] and [[Doerrier Carolina|Doerrier C]] (last update 2020-04-30) | |||
[[File:M-malic enzyme.jpg|right|300px|M and malic enzyme]] | |||
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== M<sub>''L''</sub> == | |||
== M | Β | ||
== M | == M<sub>''P''</sub> == | ||
:::: If malate-anaplerotic pathways are present, malate alone may provide mt-respiration values comparable to OXPHOS state (''P''). However, to ensure OXPHOS state measurement, a combination of NADH-linked substrates should be performed (i.e. [[PM-pathway control state|PM]], [[GM-pathway control state|GM]], [[PGM|PGM]]). SUIT-027 evaluates malate-anaplerotic pathway (malate alone in the presence of ADP) and OXPHOS state (''P'') with pyruvate&malate and pyruvate&glutamate&malate as NADH-linked substrates: | |||
:::* [[SUIT-027]] | |||
::::* DL-Protocol for isolated mitochondria and tissue homogenate (mt): [[SUIT-027 O2 ce-pce D065]] | |||
== M<sub>''E''</sub> == | |||
= | {{MitoPedia concepts | ||
|mitopedia concept=SUIT state | |||
}} | |||
Latest revision as of 01:28, 31 December 2020
- high-resolution terminology - matching measurements at high-resolution
Malate-anaplerotic pathway control state
Description
M: Malate alone does not support respiration of mt-preparations if oxaloacetate cannot be metabolized further in the absence of a source of acetyl-CoA. Transport of oxaloacetate across the inner mt-membrane is restricted particularly in liver. Mitochondrial citrate and 2-oxoglutarate (Ξ±-ketoglutarate) are depleted by antiport with malate. Succinate is lost from the mitochondria through the dicarboxylate carrier. OXPHOS capacity with malate alone is only 1.3% of that with Pyruvate&Malate in isolated rat skeletal muscle mitochondria. However, many mammalian and non-mammalian mitochondria have a mt-isoform of NADP+- or NAD(P)+-dependent malic enzyme (mtME), the latter being particularly active in proliferating cells. Then the anaplerotic pathway control state with malate alone (aN) supports high respiratory activities comparable to the NADH-linked pathway control states (N) with pyruvate&malate or glutamate&malate substrate combinations (PM-pathway control state, GM-pathway control state).
Abbreviation: M
Reference: Gnaiger 2020 BEC MitoPathways
Communicated by Gnaiger E 2016-01-24, edited by Cardoso LHD and Doerrier C (last update 2020-04-30)
ML
MP
- If malate-anaplerotic pathways are present, malate alone may provide mt-respiration values comparable to OXPHOS state (P). However, to ensure OXPHOS state measurement, a combination of NADH-linked substrates should be performed (i.e. PM, GM, PGM). SUIT-027 evaluates malate-anaplerotic pathway (malate alone in the presence of ADP) and OXPHOS state (P) with pyruvate&malate and pyruvate&glutamate&malate as NADH-linked substrates:
- DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-027 O2 ce-pce D065
ME
MitoPedia concepts: SUIT state
