Peptides from mouse DLL1 identified with O-fucose modifications.

O-fucosylated peptides were identified by neutral loss of mass corresponding to fucose (146 daltons, see Figure S1) upon fragmentation. Spectra for each glycopeptide identified here are shown in the Figure S1. All masses were converted to the equivalent of singly charged (M+H+) for the table. For each glycopeptide, the mass of the parent ion, the deglycosylated product (lacking fucose), and the difference between these (corresponding to the mass of the modification) is shown. The predicted mass of the unglycosylated peptide is also shown. All peptide masses are adjusted for carbamidomethylation of cysteines. For peptides with a mass below 2000 Da, monoisotopic masses were used. For those above 2000 Da, average masses were used. Predicted O-fucose modification sites are bold underlined, and cysteines within the consensus sequence, C2XXXX(S/T)C3 are bold. *Note that this ion lost a water (16 Daltons).