Fig. 10.

A, HCD-MS2 spectra of an HSA glycated peptide identified in the analysis of plasma by the work flow proposed in Fig. 2. Digestion with Glu-C protease enables the generation of long peptides (25 amino acid residues for this specific case). The analysis of long peptides in combination with high accuracy for precursor and fragment ions enables to take benefits from the “middle-down proteomics” concept. B, number of glycated peptides identified in plasma versus charge state of these identifications, which gives an idea about the length of the detected peptides.