Fig. 6: Release of sialylated O-glycans from bovine fetuin and protein drugs etanercept and abatacept.
From: Dual functional POGases from bacteria encompassing broader O-glycanase and adhesin activities
a O-glycans from fetuin peptides by β-elimination, POGase AS, and O-glc digestions: Top panel: O-glycans released from glycopeptides of fetuin by β-elimination (unreduced glycans); Middle panel: POGase AS released O-glycans with a 16 Da increased mass shift (reduced glycans); Bottom panel: NEB O-glycosidase (O-glc) treatment of fetuin did not yield any sialylated O-glycan peaks. b Comparative quantification of released O-glycan species by three different methods from (a). c Mono-sialylCore 1 O-glycans (m/z 895) released from denatured fetuin by POGase AS digestion. d, e: O-glycans from protein drugs released by POGase AS: glycopeptides of abatacept (d) and etanercept (e) treated by POGase AS yielded two sialylated O-glycan peaks consistent with α2,3sialylCore 1 and a minor di-sialylCore 1 peak (m/z 895, m/z 1256, respectively) as compared to the corresponding peaks (m/z 879, m/z 1240, respectively) from the β-elimination (unreduced glycans). The O-glycans from denatured proteins treated with POGase AS only yielded mono-sialylCore 1 (m/z 895). Source data are provided as a Source Data file.
