Additive effect of convergent electron flow

high-resolution terminology - matching measurements at high-resolution

Additive effect of convergent electron flow

Description

Additivity describes the princple of substrate control of mitochondrial respiration, where the additive effect of convergent CI&II electron flow is a consequence of electron flow converging at the Q-junction from respiratory Complexes I and II (CI&II e-input). Further additivity may be observed by convergent electron flow through glycerophosphate dehydrogenase and electron-transferring flavoprotein. Convergent electron flow corresponds to the operation of the TCA cycle and mitochondrial substrate supply in vivo. Convergent electron flow simultaneously through Complexes I and II (CI&II) into the Q-junction supports higher OXPHOS capacity and ETS capacity than separate electron flow through either CI or CII. Physiological substrate combinations supporting convergent CI&II e-input are required for reconstitution of intracellular TCA cycle function. The convergent CI&II effect may be completely or partially additive, suggesting that conventional bioenergetic protocols with mt-preparations have underestimated cellular OXPHOS capacities, due to the gating effect through a single branch, corresponding to additivity.

Abbreviation: A_α&β

Reference: Gnaiger 2014 MitoPathways, Gnaiger_2009_Int J Biochem Cell Biol

MitoPedia methods: Respirometry 

MitoPedia topics: Substrate and metabolite