Phospho-site assignment & manual validation of the phosphorylated peptide VLVDQ TTph GLSR obtained by Mascot analysis. The monoisotopic mass of neutral peptide Mr (calc) resulted was 1267.6173. Fixed modifications chosen were: Carbamidomethyl (C), while for variable modifications T7: Phospho (ST), with neutral losses 97.9769 (shown in table) was selected. The y5 ion and b7 are those which allowed identification of the treonine (5) as phosphorylated (ph) amino acid (T in red colour). In addition the phosphate fingerprint of the neutral loss (NL) from the parent ion is also a positive signal of phosphorylation. Six b ions and 8 y ions were continuously matched respectively.