Summary
The glycoprotein spike (S) on the surface of SARS-CoV-2 is a determinant for viral invasion and host immune response. Herein, we characterized the site-specific N-glycosylation of S protein at the level of intact glycopeptides. All 22 potential N-glycosites were identified in the S-protein protomer and were found to be preserved among the 753 SARS-CoV-2 genome sequences. The glycosites exhibited glycoform heterogeneity as expected for a human cell-expressed protein subunits. We identified masses that correspond to 157 N-glycans, primarily of the complex type. In contrast, the insect cell-expressed S protein contained 38 N-glycans, primarily of the high-mannose type. Our results revealed that the glycan types were highly determined by the differential processing of N-glycans among human and insect cells. This N-glycosylation landscape and the differential N-glycan patterns among distinct host cells are expected to shed light on the infection mechanism and present a positive view for the development of vaccines and targeted drugs.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
manuscript revised;Figures revised; author affiliations updated; Supplemental files updated.
Abbreviations
- ACE2
- angiotensin-converting enzyme II
- Cryo-EM
- cryoelectron microscopy
- E
- envelope protein
- HCoV-NL63
- human coronavirus NL63
- M
- membrane protein
- MS
- mass spectrometry
- MERS-CoV
- Middle East respiratory syndrome coronavirus
- N
- nucleocapsid protein
- RBD
- receptor-binding domain
- S
- spike protein
- SARS-CoV-2
- severe acute respiratory syndrome coronavirus
- SCE
- stepped collision energy
- Zic-HILIC
- zwitterionic hydrophilic interaction liquid chromatography