PM-pathway control state

high-resolution terminology - matching measurements at high-resolution

PM-pathway control state

Description

PM: Pyruvate & Malate.

MitoPathway control state: NADH Electron transfer-pathway state

Upstream of the NAD-junction, Pyruvate (P) is oxidatively decarboxylated to acetyl-CoA and CO₂, yielding NADH catalyzed by pyruvate dehydrogenase. Malate (M) is oxidized to oxaloacetate by mt-malate dehydrogenase located in the mitochondrial matrix. Condensation of oxaloacate with acetyl-CoA yields citrate (citrate synthase). 2-oxoglutarate (α-ketoglutarate) is formed from isocitrate (isocitrate dehydrogenase).

Abbreviation: PM

Reference: Gnaiger 2020 BEC MitoPathways

More details

» NADH electron transfer-pathway state

» Additive effect of convergent electron flow

» Respiratory complexes - more than five

» Convergent electron flow

PM_L

With PM as N-substrates, LEAK respiration L can be evaluated in the following SUIT protocols:

• SUIT-001

• DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-001 O2 mt D001
• DL-Protocol for permeabilized fibers (pfi): SUIT-001 O2 pfi D002
• DL-Protocol for permeabilized cells (pce): SUIT-001 O2 ce-pce D003
• DL-Protocol for permeabilized blood cells (PBMC and PLT): SUIT-001 O2 ce-pce D004

• SUIT-004

• DL-Protocol for permeabilized fibers (pfi): SUIT-004 O2 pfi D010

• SUIT-006

• DL-Protocol for permeabilized cells (pce): SUIT-006 O2 ce-pce D029
• DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-006 O2 mt D047

• SUIT-008

• DL-Protocol for permeabilized fibers (pfi): SUIT-008 O2 pfi D014

PM_P

With PM as N-substrates, OXPHOS capacity P can be evaluated in the following SUIT protocols:

• SUIT-001

• DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-001 O2 mt D001
• DL-Protocol for permeabilized fibers (pfi): SUIT-001 O2 pfi D002
• DL-Protocol for permeabilized cells (pce): SUIT-001 O2 ce-pce D003
• DL-Protocol for permeabilized blood cells (PBMC and PLT): SUIT-001 O2 ce-pce D004

• SUIT-004

• DL-Protocol for permeabilized fibers (pfi): SUIT-004 O2 pfi D010

• SUIT-006

• DL-Protocol for permeabilized cells (pce): SUIT-006 O2 ce-pce D029
• DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-006 O2 mt D047

• SUIT-008

• DL-Protocol for permeabilized fibers (pfi): SUIT-008 O2 pfi D014

PM_E

With PM as N-substrates, ET capacity E can be evaluated in the following SUIT protocols:

• SUIT-001

• DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-001 O2 mt D001
• DL-Protocol for permeabilized fibers (pfi): SUIT-001 O2 pfi D002
• DL-Protocol for permeabilized cells (pce): SUIT-001 O2 ce-pce D003
• DL-Protocol for permeabilized blood cells (PBMC and PLT): SUIT-001 O2 ce-pce D004

• SUIT-004

• DL-Protocol for permeabilized fibers (pfi): SUIT-004 O2 pfi D010

• SUIT-006

• DL-Protocol for permeabilized cells (pce): SUIT-006 O2 ce-pce D029
• DL-Protocol for isolated mitochondria and tissue homogenate (mt): SUIT-006 O2 mt D047

• SUIT-008

• DL-Protocol for permeabilized fibers (pfi): SUIT-008 O2 pfi D014

Linear coupling control in the N-pathway control state: L → P → E

• P-L

P-L control efficiency, j_P-L = (P-L)/P = 1-L/P, is measured in the N-pathway state, with defined coupling sites (CI, CIII, CIV).

• P-E

CCCP is titrated stepwise to maximum flux, to evaluate limitation of OXPHOS by the phosphorylation system, expressed as the E-P control efficiency j_E-P = (E-P)/E = 1-P/E.

If j_E-P>0, then the E-L coupling efficiency rather than the P-L control efficiency is the proper expression of coupling, j_E-L = (E-L)/E = 1-L/E.

Discussion

The Pyruvate anaplerotic pathway control state (pyruvate alone) is not an ET-pathway competent substrate state in most mt-preparations, since acetyl-CoA accumulates without the co-substrate (oxaloacetate) of citrate synthase.

The Malate-anaplerotic pathway control state (M alone) is not an ET-pathway competent substrate state in many mt-preparations, since oxaloacetate accumulates without the co-substrate (acetyl-CoA) of citrate synthase.

MitoPedia concepts: SUIT state