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The site of production of superoxide radical in mitochondrial Complex I is not a bound ubisemiquinone but presumably iron–sulfur cluster N2
Author(s) -
Genova Maria Luisa,
Ventura Barbara,
Giuliano Giovanni,
Bovina Carla,
Formiggini Gabriella,
Parenti Castelli Giovanna,
Lenaz Giorgio
Publication year - 2001
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(01)02850-2
Subject(s) - submitochondrial particle , superoxide , coenzyme q – cytochrome c reductase , chemistry , electron transport complex i , reactive oxygen species , iron–sulfur cluster , mitochondrial respiratory chain , respiratory chain , redox , superoxide radical , electron transfer , oxygen , mitochondrion , stereochemistry , biochemistry , photochemistry , enzyme , organic chemistry , cytochrome c
The mitochondrial respiratory chain is a powerful source of reactive oxygen species, considered as the pathogenic agent of many diseases and of aging. We have investigated the role of Complex I in superoxide radical production in bovine heart submitochondrial particles and found, by combined use of specific inhibitors of Complex I and by Coenzyme Q (CoQ) extraction from the particles, that the one‐electron donor in the Complex to oxygen is a redox center located prior to the binding sites of three different types of CoQ antagonists, to be identified with a Fe–S cluster, most probably N2 on the basis of several known properties of this cluster. Short chain CoQ analogs enhance superoxide formation, presumably by mediating electron transfer from N2 to oxygen. The clinically used CoQ analog, idebenone, is particularly effective in promoting superoxide formation.