Reaction of endogenous Coenzyme Q10 with nitrogen monoxide and its metabolite nitrogen dioxide

Redox Rep. 2019 Dec;24(1):56-61. doi: 10.1080/13510002.2019.1647005.

Abstract

Objectives: Coenzyme Q10, incorporated in DOPC lyposomes or naturally present in liver bovine mitochondria or in human blood plasma, was reacted with nitrogen dioxide •NO2 or with a •NO/•NO2 mixture. Methods and Results: The reaction course was monitored by Electron Paramagnetic Resonance (EPR) spectroscopy and in all cases the formation of a di-tert-alkyl nitroxide was observed, deriving from the addition of •NO2 to one of the double bonds, most likely the terminal one, of the isoprenic chain. The rate constant for nitroxide formation was also determined by EPR spectroscopy and an initial rate of ca. 7 × 10-8 M s-1 was obtained.

Keywords: Coenzyme Q; addition reaction; isoprenic chain; liposomes; mitochondria; nitrogen dioxide; nitroxide; plasma.

MeSH terms

  • Animals
  • Cattle
  • Kinetics
  • Liposomes / metabolism
  • Mice
  • Mitochondria, Liver / metabolism
  • Molecular Structure
  • Nitric Oxide / blood*
  • Nitric Oxide / metabolism
  • Nitrogen Dioxide / blood*
  • Nitrogen Dioxide / metabolism
  • Ubiquinone / analogs & derivatives*
  • Ubiquinone / blood
  • Ubiquinone / metabolism

Substances

  • Liposomes
  • Ubiquinone
  • Nitric Oxide
  • coenzyme Q10
  • Nitrogen Dioxide