O. Curcuruto et al., Peptide nitration by peroxynitrite: Characterisation of the nitration sites by liquid chromatography tandem mass spectrometry, RAP C MASS, 13(3), 1999, pp. 156-163
A number of recent studies have demonstrated that peroxynitrite (ONOO-) can
react with a host of biomolecules, particularly those containing aromatic
amino acid residues, resulting in a number of modifications which have been
found in association with diverse pathological conditions, Electrospray io
nisation tandem mass spectrometry with and without liquid chromatographic s
eparation has been used to examine a series of model peptides following the
ir treatment with peroxynitrite at physiological pH, The mass spectra of se
quences containing two tyrosine residues showed the formation of both monon
itrated and dinitrated species, while those with phenylalanine showed no de
tectable nitration. Tryptic digests of two of the investigated peptides wer
e also examined by liquid chromatography/electrospray mass spectrometry, wh
ich yielded further information on the competition for NO2 by multiple nitr
ation sites within a given sequence. In addition, tryptic digests of the mo
nonitrated component of sequences containing tyrosine and tryptophan indica
ted that mononitration was limited to tyrosine. Furthermore, some of the pr
esented data indicate that, as well as nitrotyrosine and nitrotryptophan fo
rmation, the reaction of ONOO- cars result in oxidation as well as the form
ation of labile adducts with NO2, Copyright (C) 1999 John Wiley & Sons, Ltd
.