Feedback Regulation and Time Hierarchy of Oxidative Phosphorylation in Cardiac Mitochondria.
Biophys J
; 110(4): 972-80, 2016 Feb 23.
Article
en En
| MEDLINE
| ID: mdl-26910434
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.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fosforilación Oxidativa
/
Adenosina Trifosfato
/
Retroalimentación Fisiológica
/
Mitocondrias Cardíacas
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
Biophys J
Año:
2016
Tipo del documento:
Article