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A Non‐damaging Method to Analyze the Configuration and Dynamics of Nitrotyrosines in Proteins
Author(s) -
DíazMoreno Irene,
Nieto Pedro M.,
Del Conte Rebecca,
Gairí Margarida,
GarcíaHeredia José M.,
De la Rosa Miguel A.,
DíazQuintana Antonio
Publication year - 2012
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201103413
Subject(s) - nitration , heteronuclear single quantum coherence spectroscopy , chemistry , peroxynitrite , tyrosine , reagent , heteronuclear molecule , chemical shift , stereochemistry , biochemistry , biophysics , nuclear magnetic resonance spectroscopy , organic chemistry , enzyme , biology , superoxide
Often, deregulation of protein activity and turnover by tyrosine nitration drives cells toward pathogenesis. Hence, understanding how the nitration of a protein affects both its function and stability is of outstanding interest. Nowadays, most of the in vitro analyses of nitrated proteins rely on chemical treatment of native proteins with an excess of a chemical reagent. One such reagent, peroxynitrite, stands out for its biological relevance. However, given the excess of the nitrating reagent, the resulting in vitro modification could differ from the physiological nitration. Here, we determine unequivocally the configuration of distinct nitrated‐tyrosine rings in single‐tyrosine mutants of cytochrome c . We aimed to confirm the nitration position by a non‐destructive method. Thus, we have resorted to 1 H‐ 15 N heteronuclear single quantum coherence(HSQC) spectra to identify the 3 J (NH) correlation between a 15 N‐tagged nitro group and the adjacent aromatic proton. Once the chemical shift of this proton was determined, we compared the 1 H‐ 13 C HSQC spectra of untreated and nitrated samples. All tyrosines were nitrated at ε positions, in agreement to previous analysis by indirect techniques. Notably, the various nitrotyrosine residues show a different dynamic behaviour that is consistent with molecular dynamics computations.