Cardoso 2022 Abstract Bioblast

Cardoso Luiza HD, Doerrier C, Donnelly C, Komlódi T, Gnaiger E (2022) Redox monitoring and respiration - a new horizon with the NextGen-O2k. Bioblast 2022: BEC Inaugural Conference.

Link: Bioblast 2022: BEC Inaugural Conference

Cardoso Luiza HD, Doerrier Carolina, Donnelly Chris, Komlódi Timea, Gnaiger Erich (2022)

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 [1] are linked in the N-pathway but are regulated independently by several convergent electron entries into the Q-junction [2]. 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 [3] 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 [2]. Monitoring of respiration together with NAD(P)H autofluorescence and Q-redox state [1] provides unique analytical and diagnostic power in the study of mitochondrial respiratory control at the N- and Q-junctions.

1. 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
2. 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
3. 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.

List of abbreviations, terms and definitions - MitoPedia

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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