Fig. 3.

MS analysis of O-glycans derived from humanized mZP. O-glycans were isolated from humanized mZP derived from 100 ovaries, permethylated, and subjected to reverse-phase chromatography on Sep-Pak C₁₈ cartridges, as described (13). The MALDI-TOF mass spectrum of the 35% aqueous acetonitrile fraction from the cartridge is shown in A. An additional signal (m/z 1187) corresponding to Hex₃HexNAc₂ was observed in the 50% aqueous acetonitrile fraction and is shown in the Inset to A. Signals attributable to O-glycans are annotated with roman numbers, as outlined in Fig. 2. The sequences of each of these components were confirmed by CAD ES-MS/MS. Data from these experiments are presented in B–E for m/z 779, 983, 1,024, and 1,187, respectively, and fragment ions are assigned on the structures shown in Insets.