FIGURE 3.
Identification of a Tyr-nitration site in OASA1. LC-MS/MS analysis of nitrated OASA1 and non-nitrated control allowed the identification of Y*LSTVLFDATR peptide with nitrated or non-nitrated Tyr302, respectively (A). The 22.49 Da shift of the double charged peptide indicates nitration of Tyr302. Ion score (MASCOT) of the nitrated and non-nitrated peptides are shown. The MS spectra corresponding to Y(NO2)LSTVLFDATR (Z = 2; m/z = 665.82) is shown (B). NO2-Y indicates the presence of the nitrated tyrosine immonium ion mass in the LC-MS/MS spectra. Identified y and b ion series are pointed out.