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Plasma membrane NADH‐coenzyme Q 0 reductase generates semiquinone radicals and recycles vitamin E homologue in a superoxide‐dependent reaction
Author(s) -
Kagan Valerian E,
Arroyo Antonio,
Tyurin Vladimir A,
Tyurina Yulia Y,
Villalba Jose M,
Navas Placido
Publication year - 1998
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(98)00482-7
Subject(s) - trolox , radical , semiquinone , chemistry , vitamin e , reductase , cofactor , biochemistry , superoxide , antioxidant , vitamin , vitamin c , enzyme , photochemistry , quinone , antioxidant capacity
We investigated the ability of plasma membrane CoQ reductase (PMQR) purified from pig liver to reduce phenoxyl radicals of a vitamin E homologue, Trolox. We report that NADH‐driven one‐electron reduction of CoQ 0 catalyzed by PMQR produced CoQ 0 semiquinone radical and CoQ 0 H 2 . These in turn, recycle vitamin E homologue, Trolox, via reducing its phenoxyl radical. A significant part of NADH/PMQR‐catalyzed reduction of CoQ 0 (and Trolox recycling) was superoxide‐dependent. Overall, our results demonstrate that PMQR in the model system used can act as an antioxidant enzyme that recycles water‐soluble homologues of coenzyme Q and vitamin E.