Figure 5
From: Fluorescent glycan fingerprinting of SARS2 spike proteins
O-Glycan of the RBD domain of SARS-CoV-2 spike protein varies depending on the host cells. (A) Strategy for O-glycan conversion and labeling. (B) RBD expressed in CHO (RC), HEK293 (RH), Sf21(RS) and Tn (RT) cells were probed for O-glycans with CMP-Cy5-Neu5Ac and ST3Gal1. The proteins were directly labeled or labeled after pretreatment with C. perfringens neuraminidase alone (Neu) or in combination with Endo EF (EF). Densitometry analysis indicated that neuraminidase treatment resulted in a 71% increase in labeling of the RBD protein expressed in HEK293 cells. (C) RBD protein expressed in Sf21 cells (RS) pretreated with GCNT1 alone or together with B4GalT1 was labeled with ST3Gal1 and then digested with trypsin. RBD protein fused to the IgG Fc domain expressed in HEK293 cells (RH/Fc), RH and RC samples were also labeled and digested by trypsin and run alongside the RS samples.
