The role of Coenzyme Q in mitochondrial electron transport.
In mitochondria, most Coenzyme Q is free in the lipid bilayer; the question as to whether tightly bound, non-exchangeable Coenzyme Q molecules exist in mitochondrial complexes is still an open question. We review the mechanism of inter-complex electron transfer mediated by ubiquinone and discuss the kinetic consequences of the supramolecular organization of the respiratory complexes (randomly dispersed vs. super-complexes) in terms of Coenzyme Q pool behavior vs. metabolic channeling, respectively, both in physiological and in some pathological conditions. As an example of intra-complex electron transfer, we discuss in particular Complex I, a topic that is still under active investigation.
Lenaz
Giorgio
G
Dipartimento di Biochimica, Università di Bologna, Via Irnerio 48, 40126 Bologna, Italy. lenaz@biocfarm.unibo.it
Fato
Romana
R
Formiggini
Gabriella
G
Genova
Maria Luisa
ML
D000818:Animals; D001671:Biochemistry / Q000379:methods; D004579:Electron Transport; D042967:Electron Transport Complex I; D004583:Electrons; D006801:Humans; D007700:Kinetics; D008051:Lipid Bilayers / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D051336:Mitochondrial Membranes / Q000378:metabolism; D008954:Models, Biological; D008958:Models, Molecular; D010101:Oxygen Consumption; D014451:Ubiquinone / Q000502:physiology*
D008051:Lipid Bilayers; D014451:Ubiquinone; D042967:Electron Transport Complex I