Peroxynitrite formation in nitric oxide-exposed submitochondrial particles: detection, oxidative damage and catalytic removal by Mn-porphyrins.

Published

Journal Article

Peroxynitrite (ONOO(-)) formation in mitochondria may be favored due to the constant supply of superoxide radical (O(2)(∙-)) by the electron transport chain plus the facile diffusion of nitric oxide ((∙)NO) to this organelle. Herein, a model system of submitochondrial particles (SMP) in the presence of succinate plus the respiratory inhibitor antimycin A (to increase O(2)(∙-) rates) and the (∙)NO-donor NOC-7 was studied to directly establish and quantitate peroxynitrite by a multiplicity of methods including chemiluminescence, fluorescence and immunochemical analysis. While all the tested probes revealed peroxynitrite at near stoichiometric levels with respect to its precursor radicals, coumarin boronic acid (a probe that directly reacts with peroxynitrite) had the more straightforward oxidation profile from O(2)(∙-)-forming SMP as a function of the (∙)NO flux. Interestingly, immunospintrapping studies verified protein radical generation in SMP by peroxynitrite. Substrate-supplemented SMP also reduced Mn(III)porphyrins (MnP) to Mn(II)P under physiologically-relevant oxygen levels (3-30 μM); then, Mn(II)P were capable to reduce peroxynitrite and protect SMP from the inhibition of complex I-dependent oxygen consumption and protein radical formation and nitration of membranes. The data directly support the formation of peroxynitrite in mitochondria and demonstrate that MnP can undergo a catalytic redox cycle to neutralize peroxynitrite-dependent mitochondrial oxidative damage.

Full Text

Duke Authors

Cited Authors

  • Valez, V; Cassina, A; Batinic-Haberle, I; Kalyanaraman, B; Ferrer-Sueta, G; Radi, R

Published Date

  • January 1, 2013

Published In

Volume / Issue

  • 529 / 1

Start / End Page

  • 45 - 54

PubMed ID

  • 23142682

Pubmed Central ID

  • 23142682

Electronic International Standard Serial Number (EISSN)

  • 1096-0384

Digital Object Identifier (DOI)

  • 10.1016/j.abb.2012.10.012

Language

  • eng

Conference Location

  • United States