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Mitochondrial production of reactive oxygen species: Role of Complex I and quinone analogues
Author(s) -
Fato Romana,
Bergamini Christian,
Leoni Serena,
Lenaz Giorgio
Publication year - 2008
Publication title -
biofactors
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.204
H-Index - 94
eISSN - 1872-8081
pISSN - 0951-6433
DOI - 10.1002/biof.5520320105
Subject(s) - reactive oxygen species , electron transport complex i , chemistry , rotenone , mitochondrial respiratory chain , coenzyme q – cytochrome c reductase , oxidative stress , quinone , respiratory chain , electron transport chain , mitochondrion , oxygen , oxidative phosphorylation , biochemistry , superoxide , biophysics , stereochemistry , enzyme , biology , cytochrome c , organic chemistry
Mitochondrial reactive oxygen species (ROS) are mainly produced by the respiratory chain enzymes. The sites for ROS production in mitochondrial respiratory chain are normally ascribed to the activity of Complex I and III. The presence of specific inhibitors modulates reactive oxygen species production in Complex I: inhibitors such as rotenone induce a strong ROS increase, while inhibitors such as stigmatellin prevent it. We have investigated the effect of hydrophilic quinones on Complex I ROS production in presence of different inhibitors. Some short chain quinones are Complex I inhibitors (CoQ 2 , idebenone and its derivatives), while CoQ 1 , decylubiquinone (DB) and duroquinone (DQ) are good electron acceptors from Complex I. Our results show that the ability of short chain quinones to induce an oxidative stress depends on the site of interaction with Complex I and on their physical‐chemical characteristics. We can conclude that hydrophilic quinones may enhance oxidative stress by interaction with the electron escape sites on Complex I while more hydrophobic quinones can be reduced only at the physiological quinone reducing site without reacting with molecular oxygen.