GMS-pathway control state

From Bioblast

high-resolution terminology - matching measurements at high-resolution

GMS-pathway control state



GMS: Glutamate & Malate & Succinate.

MitoPathway control: NS

Transaminase catalyzes the reaction from oxaloacetate to 2-oxoglutarate, which then establishes a cycle without generation of citrate. OXPHOS is higher with GS (CI&II) compared to GM (CI) or SRot (CII). This documents an additive effect of convergent CI&II electron flow to the Q-junction, with consistent results obtained with permeabilized muscle fibres and isolated mitochondria (Gnaiger 2009).

Abbreviation: GMS

Reference: Gnaiger 2020 BEC MitoPathways

More details
Β» Additive effect of convergent electron flow
Β» Respiratory complexes - more than five
Β» OctPGMSGp pathway control state
Β» Convergent electron flow
Β» NS-pathway control state


GMS pathway in the LEAK state can be evaluated in the following SUIT protocols:


GMS pathway in the OXPHOS state can be evaluated in the following SUIT protocols:


GMS pathway in the ET state can be evaluated in the following SUIT protocols:


In human skeletal muscle mitochondria (25 Β°C), Rasmussen and Rasmussen (2000) obtained CI/CI&II flux ratios of 0.7 (0.6) for OXPHOS (or ETS) with glutamate&malate (8+4 mM) and glutamate&succinate (4+8 mM), and CII/CI&II flux ratios of 0.8 (0.6) for OXPHOS (or ETS). The GMP/GMSE and S(Rot)E/GMSE flux control ratios are 0.50 and 0.55 in human vastus lateralis (Pesta et al 2011).
Due to the lower H+/O2 stoichiometry in succinate respiration compared to CI-linked respiration (two versus three coupling sites), the CI/CI&II ratio is lower for LEAK respiration (0.3 to 0.4; Garait et al 2005) compared to OXPHOS capacity.
In human skeletal muscle, the phosphorylation system is more limiting at the highest OXPHOS activity with glutamate&succinate, at a P/E ratio (GSP/GSE) of 0.69 versus 0.80 with glutamate&malate (Rasmussen and Rasmussen 2000). Failure of obtaining a further stimulation of coupled OXPHOS in human skeletal muscle mitochondria with GMS by uncoupling (Kunz et al 2000) can be explained by the high FCCP concentration applied (10 Β΅M) which is known to inhibit respiration (Steinlechner-Maran et al 1996). In mouse skeletal muscle, however, the P/E ratio is actually 1.0 (Aragones et al 2008), which contrasts with the significant limitation of OXPHOS capacity by the phosphorylation system in humans

MitoPedia concepts: SUIT state 

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