Protein Tyrosine Nitration and Thiol Oxidation by Peroxynitrite—Strategies to Prevent These Oxidative Modifications

International Journal of Molecular Sciences

Andreas Daiber⁵  Steffen Daub⁵  Markus Bachschmid³  Stefan Schildknecht²  Matthias Oelze⁵  Sebastian Steven⁵  Patrick Schmidt²  Alexandra Megner²  Masayuki Wada¹  Tadashi Tanabe¹  Thomas Münzel⁵  Serge Bottari⁴ 

[1] Department of Pharmacology, National Cardiovascular Center Research Institute, Suita, Osaka 565-8565, Japan; E-Mail:;Department of Biology, University of Konstanz, Konstanz 78457, Germany; E-Mails:;Vascular Biology Section, Whitaker Cardiovascular Institute, Boston University Medical Center, Boston, MA 02118, USA; E-Mail:;Laboratory of Fundamental and Applied, Bioenergetics, INSERM U1055, Grenoble Universités and Pôle de Biologie, CHU, Grenoble 38400, France; E-Mail:;2nd Medical Clinic, Molecular Cardiology, Medical Center of the Johannes Gutenberg University, Mainz 55131, Germany; E-Mails:

关键词: nitric oxide;    superoxide;    peroxynitrite;    protein tyrosine nitration;    thiol oxidation;    peroxynitrite scavengers;    prostacyclin synthase;   

DOI  :  10.3390/ijms14047542

来源: mdpi

【 摘 要 】

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.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland