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Protein Tyrosine Nitration and Thiol Oxidation by Peroxynitrite—Strategies to Prevent These Oxidative Modifications
Medical Clinic, Molecular Cardiology, Medical Center of the Johannes Gutenberg University, Mainz 55131, Germany
Vascular Biology Section, Whitaker Cardiovascular Institute, Boston University Medical Center, Boston, MA 02118, USA
Department of Biology, University of Konstanz, Konstanz 78457, Germany
Department of Pharmacology, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan
Laboratory of Fundamental and Applied, Bioenergetics, INSERM U1055, Grenoble Universités and Pôle de Biologie, CHU, Grenoble 38400, France
These authors contributed equally to this work.Received: 31 December 2012
* Author to whom correspondence should be addressed.
Received: 31 December 2012; in revised form: 11 March 2013 / Accepted: 18 March 2013 / Published: 8 April 2013
Abstract: The reaction product of nitric oxide and superoxide, peroxynitrite, is a potent biological oxidant. The most important oxidative protein modifications described for peroxynitrite are cysteine-thiol oxidation and tyrosine nitration. We have previously demonstrated that intrinsic heme-thiolate (P450)-dependent enzymatic catalysis increases the nitration of tyrosine 430 in prostacyclin synthase and results in loss of activity which contributes to endothelial dysfunction. We here report the sensitive peroxynitrite-dependent nitration of an over-expressed and partially purified human prostacyclin synthase (3.3 μM) with an EC50 value of 5 μM. Microsomal thiols in these preparations effectively compete for peroxynitrite and block the nitration of other proteins up to 50 μM peroxynitrite. Purified, recombinant PGIS showed a half-maximal nitration by 10 μM 3-morpholino sydnonimine (Sin-1) which increased in the presence of bicarbonate, and was only marginally induced by freely diffusing NO2-radicals generated by a peroxidase/nitrite/hydrogen peroxide system. Based on these observations, we would like to emphasize that prostacyclin synthase is among the most efficiently and sensitively nitrated proteins investigated by us so far. In the second part of the study, we identified two classes of peroxynitrite scavengers, blocking either peroxynitrite anion-mediated thiol oxidations or phenol/tyrosine nitrations by free radical mechanisms. Dithiopurines and dithiopyrimidines were highly effective in inhibiting both reaction types which could make this class of compounds interesting therapeutic tools. In the present work, we highlighted the impact of experimental conditions on the outcome of peroxynitrite-mediated nitrations. The limitations identified in this work need to be considered in the assessment of experimental data involving peroxynitrite.
Keywords: nitric oxide; superoxide; peroxynitrite; protein tyrosine nitration; thiol oxidation; peroxynitrite scavengers; prostacyclin synthase
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Daiber, A.; Daub, S.; Bachschmid, M.; Schildknecht, S.; Oelze, M.; Steven, S.; Schmidt, P.; Megner, A.; Wada, M.; Tanabe, T.; Münzel, T.; Bottari, S.; Ullrich, V. Protein Tyrosine Nitration and Thiol Oxidation by Peroxynitrite—Strategies to Prevent These Oxidative Modifications. Int. J. Mol. Sci. 2013, 14, 7542-7570.
Daiber A, Daub S, Bachschmid M, Schildknecht S, Oelze M, Steven S, Schmidt P, Megner A, Wada M, Tanabe T, Münzel T, Bottari S, Ullrich V. Protein Tyrosine Nitration and Thiol Oxidation by Peroxynitrite—Strategies to Prevent These Oxidative Modifications. International Journal of Molecular Sciences. 2013; 14(4):7542-7570.
Daiber, Andreas; Daub, Steffen; Bachschmid, Markus; Schildknecht, Stefan; Oelze, Matthias; Steven, Sebastian; Schmidt, Patrick; Megner, Alexandra; Wada, Masayuki; Tanabe, Tadashi; Münzel, Thomas; Bottari, Serge; Ullrich, Volker. 2013. "Protein Tyrosine Nitration and Thiol Oxidation by Peroxynitrite—Strategies to Prevent These Oxidative Modifications." Int. J. Mol. Sci. 14, no. 4: 7542-7570.