Cardoso 2022 Abstract Bioblast
Event: Bioblast 2022
NADH-linked substrates (N-substrates) of TCA-cycle and other mt-matrix dehydrogenases feed electrons through the N-junction into Complex I. The redox states of the NAD-pool — defined as the sum of NAD(P)+ and NAD(P)H — and of the electron transfer system (ETS)-reactive coenzyme Q-pool  are linked in the N-pathway but are regulated independently by several convergent electron entries into the Q-junction . Our results obtained with HRR and the NADH- and Q-Modules of the NextGen-O2k show that complementary to ET-pathway control of respiratory rate and redox state (redox push by electron input), coupling control exerts opposite effects on the metabolic parameters. Whereas redox push reduces the N- and Q-pool in the LEAK state at low O2 flux and high protonomotive force pmF, stimulation of O2 flux by ADP in the OXPHOS state  is accompanied by a redox pull to the oxidized state. Under these conditions, ET-pathways converging at the Q-junction yield partial additivity of O2 flux, when ET-capacity downstream of Q and phosphorylation capacity exert flux control . Monitoring of respiration together with NAD(P)H autofluorescence and Q-redox state  provides unique analytical and diagnostic power in the study of mitochondrial respiratory control at the N- and Q-junctions.
- Komlódi T, Cardoso LHD, Doerrier C, Moore AL, Rich PR, Gnaiger E (2021) Coupling and pathway control of coenzyme Q redox state and respiration in isolated mitochondria. Bioenerg Commun 2021.3. https://doi.org/10.26124/bec:2021-0003
- Gnaiger E (2020) Mitochondrial pathways and respiratory control. An introduction to OXPHOS analysis. 5th ed. Bioenerg Commun 2020.2. https://doi.org/10.26124/bec:2020-0002
- Gnaiger E et al ― MitoEAGLE Task Group (2020) Mitochondrial physiology. Bioenerg Commun 2020.1. https://doi.org/10.26124/bec:2020-0001.v1
• O2k-Network Lab: AT Innsbruck Oroboros
Affiliations and support
- Oroboros Instruments GmbH, Innsbruck, Austria
- This work was part of the Oroboros NextGen-O2k project, with funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement nº 859770.
Labels: MiParea: Respiration
Organism: Mouse Tissue;cell: Liver, HEK Preparation: Permeabilized cells, Isolated mitochondria
Coupling state: LEAK, OXPHOS, ET Pathway: N, S, NS, ROX HRR: Oxygraph-2k, NextGen-O2k