IBIMOL   23987
INSTITUTO DE BIOQUIMICA Y MEDICINA MOLECULAR PROFESOR ALBERTO BOVERIS
Unidad Ejecutora - UE
artículos
Título:
Effects of rotenone and pyridaben on complex I electron transfer and on mitochondrial nitric oxide synthase functional activity
Autor/es:
NAVARRO A; BÁNDEZ MJ; GÓMEZ C; REPETTO MG; BOVERIS A
Revista:
JOURNAL OF BIOENERGETICS AND BIOMEMBRANES
Editorial:
SPRINGER/PLENUM PUBLISHERS
Referencias:
Año: 2010 vol. 42 p. 405 - 412
ISSN:
0145-479X
Resumen:
Rotenone and pyridaben were tested on activities and properties of rat
brain mitochondria determining Ki (inhibitor concentration at half
maximal inhibition) and Imax (% of inhibition at maximal inhibitor
concentration). The assayed activities were complexes I, II and IV,
respiration in states 3, 3u (uncoupled) and 4, biochemical and
functional activities of mitochondrial nitric oxide synthase (mtNOS),
and inner membrane potential. Selective inhibitions of complex I
activity, mitochondrial respiration and membrane potential with
malate-glutamate as substrate were observed, with a Ki of 0.28-0.36 nmol
inhibitor/mg of mitochondrial protein. Functional mtNOS activity was
half-inhibited at 0.70-0.74 nmol inhibitor/mg protein in state 3
mitochondria and at 2.52-2.98 nmol inhibitor/mg protein in state 3u
mitochondria. This fact is interpreted as an indication of mtNOS being
structurally adjacent to complex I with an intermolecular mtNOS-complex I
hydrophobic bonding that is stronger at high Δψ and weaker at low Δψ.