In the LC-MS/MS analysis of conjugates where two stabilization pathways coexist (Figure ) we noticed that the number of the conjugation sites based on the identification of type 2 peptides with the hydrolyzed thiosuccinimide linker and thiazine linkers were very similar . However, the number of MS/MS assigned to type 2 peptides with the hydrolyzed linker increased considerably the number of supporting MS/MS spectra thus allowing a more reliable identification of the conjugation sites .