Proton re-uptake partitioning between uncoupling protein and ATP synthase during benzohydroxamic acid-resistant state 3 respiration in tomato fruit mitochondria

Wieslawa Jarmuszkiewicz, Andrea Miyasaka Almeida, Anibal E. Vercesi, Francis E. Sluse, Claudine M. Sluse-Goffart

Resultado de la investigación: Contribución a una revistaArtículo

35 Citas (Scopus)

Resumen

The yield of oxidative phosphorylation in isolated tomato fruit mitochondria depleted of free fatty acids remains constant when respiratory rates are decreased by a factor of 3 by the addition of n-butyl malonate. This constancy makes the determination of the contribution of the linoleic acid-induced energy-dissipating pathway by the ADP/O method possible. No decrease in membrane potential is observed in state 3 respiration with increasing concentration of n-butyl malonate, indicating that the rate of ATP synthesis is steeply dependent on membrane potential. Linoleic acid decreases the yield of oxidative phosphorylation in a concentration-dependent manner by a pure protonophoric process like that in the presence of FCCP. ADP/O measurements allow calculation of the part of respiration leading to ATP synthesis and the part of respiration sustained by the dissipative H+ re- uptake induced by linoleic acid. Respiration sustained by this energy- dissipating process remains constant at a given LA concentration until more than 50% inhibition of state 3 respiration by n-butyl malonate is achieved. The energy dissipative contribution to oxygen consumption is proposed to be equal to the protonophoric activity of plant uncoupling protein divided by the intrinsic H+/O of the cytochrome pathway. It increases with linoleic acid concentration, taking place at the expense of ADP phosphorylation without an increase in the respiration.

Idioma originalInglés
Páginas (desde-hasta)13315-13320
Número de páginas6
PublicaciónJournal of Biological Chemistry
Volumen275
N.º18
DOI
EstadoPublicada - 5 may 2000

Áreas temáticas de ASJC Scopus

  • Bioquímica
  • Biología celular
  • Biología molecular

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