Vinnakota 2016a Biophys J

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Vinnakota KC, Bazil JN, Van den Bergh F, Wiseman RW, Beard DA (2016) Feedback regulation and time hierarchy of oxidative phosphorylation in cardiac mitochondria. Biophys J 110:972-80.

» PMID: 26910434 Open Access

Vinnakota KC, Bazil JN, Van den Bergh F, Wiseman RW, Beard DA (2016) Biophys J

Abstract: To determine how oxidative ATP synthesis is regulated in the heart, the responses of cardiac mitochondria oxidizing pyruvate to alterations in [ATP], [ADP], and inorganic phosphate ([Pi]) were characterized over a range of steady-state levels of extramitochondrial [ATP], [ADP], and [Pi]. Evolution of the steady states of the measured variables with the flux of respiration shows that: (1) a higher phosphorylation potential is achieved by mitochondria at higher [Pi] for a given flux of respiration; (2) the time hierarchy of oxidative phosphorylation is given by phosphorylation subsystem, electron transport chain, and substrate dehydrogenation subsystems listed in increasing order of their response times; (3) the matrix ATP hydrolysis mass action ratio [ADP] × [Pi]/[ATP] provides feedback to the substrate dehydrogenation flux over the entire range of respiratory flux examined in this study; and finally, (4) contrary to previous models of regulation of oxidative phosphorylation, [Pi] does not modulate the activity of complex III.

Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Keywords: Decylubiquinone

O2k-Network Lab: US MI Ann Arbor Beard DA, US MI East Lansing Bazil JN

Labels: MiParea: Respiration 

Organism: Rat  Tissue;cell: Heart  Preparation: Isolated mitochondria 

Regulation: ADP, ATP, Flux control, Phosphate  Coupling state: LEAK, OXPHOS  Pathway:HRR: Oxygraph-2k, TPP