Plasma membrane NADH-coenzyme Q0 reductase generates semiquinone radicals and recycles vitamin E homologue in a superoxide-dependent reaction

FEBS Lett. 1998 May 22;428(1-2):43-6. doi: 10.1016/s0014-5793(98)00482-7.

Abstract

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 CoQ0 catalyzed by PMQR produced CoQ0 semiquinone radical and CoQoH2. These in turn, recycle vitamin E homologue, Trolox, via reducing its phenoxyl radical. A significant part of NADH/PMQR-catalyzed reduction of CoQ0 (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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Benzoquinones / metabolism*
  • Catalysis
  • Cell Membrane
  • Chromans / metabolism
  • Electron Transport Complex I
  • Linoleic Acid / metabolism
  • Lipoxygenase / metabolism
  • NADH, NADPH Oxidoreductases / metabolism*
  • Oxidation-Reduction
  • Phenols
  • Superoxides / metabolism*
  • Swine
  • Vitamin E / metabolism*

Substances

  • Benzoquinones
  • Chromans
  • Phenols
  • Superoxides
  • Vitamin E
  • phenoxy radical
  • ubiquinone-O
  • Linoleic Acid
  • Lipoxygenase
  • NADH, NADPH Oxidoreductases
  • Electron Transport Complex I
  • 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid