Rapid peroxynitrite reduction by human peroxiredoxin 3: Implications for the fate of oxidants in mitochondria

• Published in: Free radical biology & medicine 2019-01, Vol.130, p.369-378
• Main Authors: De Armas, María Inés, Esteves, Romina, Viera, Nicolás, Reyes, Aníbal M., Mastrogiovanni, Mauricio, Alegria, Thiago G.P., Netto, Luis E.S., Tórtora, Verónica, Radi, Rafael, Trujillo, Madia
• Format: Article
• Language: English
• Subjects: Carbon Dioxide - metabolism; Cysteine - metabolism; Humans; Hydrogen Peroxide - metabolism; Kinetics; Mitochondria; Mitochondria - metabolism; Oxidants - metabolism; Oxidation-Reduction; Peroxiredoxin; Peroxiredoxin III - genetics; Peroxiredoxin III - metabolism; Peroxiredoxins - genetics; Peroxynitrite; Peroxynitrous Acid - metabolism; Protein Processing, Post-Translational - genetics; Signal Transduction - genetics; Sulfenic acid; Tyrosine nitration
• ISSN: 0891-5849; 1873-4596
• DOI: 10.1016/j.freeradbiomed.2018.10.451

Mitochondria are main sites of peroxynitrite formation. While at low concentrations mitochondrial peroxynitrite has been associated with redox signaling actions, increased levels can disrupt mitochondrial homeostasis and lead to pathology. Peroxiredoxin 3 is exclusively located in mitochondria, where it has been previously shown to play a major role in hydrogen peroxide reduction. In turn, reduction of peroxynitrite by peroxiredoxin 3 has been inferred from its protective actions against tyrosine nitration and neurotoxicity in animal models, but was not experimentally addressed so far. Herein, we demonstrate the human peroxiredoxin 3 reduces peroxynitrite with a rate constant of 1 × 107 M−1 s−1 at pH 7.8 and 25 °C. Reaction with hydroperoxides caused biphasic changes in the intrinsic fluorescence of peroxiredoxin 3: the first phase corresponded to the peroxidatic cysteine oxidation to sulfenic acid. Peroxynitrite in excess led to peroxiredoxin 3 hyperoxidation and tyrosine nitration, oxidative post-translational modifications that had been previously identified in vivo. A significant fraction of the oxidant is expected to react with CO2 and generate secondary radicals, which participate in further oxidation and nitration reactions, particularly under metabolic conditions of active oxidative decarboxylations or increased hydroperoxide formation. Our results indicate that both peroxiredoxin 3 and 5 should be regarded as main targets for peroxynitrite in mitochondria. [Display omitted] •Human Prx3 rapidly reduces peroxynitrite.•Prx3 intrinsic fluorescence presents biphasic changes upon oxidation.•Peroxynitrite in excess leads to Prx3 nitration and hyperoxidation.•Both Prx3 and Prx5 are predicted to be main targets for mitochondrial peroxynitrite.