The interaction of Q
analogs, particularly hydroxydecyl benzoquinone (idebenone), with the
respiratory complexes of heart mitochondria.
Esposti MD, Ngo A, Ghelli A, Benelli B,
Carelli V,
McLennan H, Linnane AW.
Centre for Molecular Biology and Medicine,
Monash University, Melbourne,
Victoria, Australia.
Arch Biochem Biophys 1996 Jun 15;330(2):395-400
Abstract
We have studied the interaction of
idebenone with
the energy-conserving complexes of the respiratory chain in beef heart
mitochondria and compared its energetic efficiency with that of other analogs
of coenzyme Q. Idebenone is a very effective substrate for succinate:Q
reductase and ubiquinol:cytochrome c reductase, but it is clearly a poor
substrate for NADH:Q reductase (complex I). Indeed, idebenone is a strong
inhibitor of both the redox and proton pumping activity of complex I, showing
effects in part similar to those of coenzyme Q-2. However, the mechanism of
idebenone interaction with complex I may be different from that of Q-2 because
of its different sensitivity to inhibitors. The possible relevance of the
present findings to the therapeutic use of idebenone is discussed.
