Glycopeptide CID-MS/MS spectra from the tail tube subunit of Corndog (gp49, top), the capsid subunit from Che8 (gp6, middle), and a minor capsid subunit of Myrna (gp98, bottom) from band 1; the precursor ions were m/z 1,516.63+, 1,202.83+, and 1,351.45+, respectively (underlined inFigureS1). Glycan oxonium ions (m/z 163.1, 204.1, 325.2, 366.1, etc.) are present in the lower half of the MS/MS spectra. Partial methylation of hexoses in Corndog and Che8 is evident by the presence of the oxonium ions at m/z 177.1, 339.2, and 380.2. Fragment ions corresponding to the peptide (Pep) and the peptide linked to HexNAc (Pep+HexNAc) are identified in all the MS/MS spectra. Ions marked with an asterisk in the Corndog spectrum are derived from a co-eluting peptide and are unrelated to the glycopeptide under investigation. Details of the MS analyses are indataset S1. HexNAc, N-acetylhexosamine; Hex, unmodified hexose; Me, methyl.
