The Effect of  <i>N</i>-Glycosylation of SARS COV-2 Spike Protein on the Virus Interaction With the Host Cell ACE2 Receptor

Abstract

The densely glycosylated spike (S) protein highly exposed on severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) surface mediates host cell entry by binding to the receptor angiotensin-converting enzyme 2 (ACE2). However, the role of glycosylation has not been fully understood. In the present study, we investigated the effect of different N-glycosylation of S1 protein on its binding to ACE2. Using real-time surface plasmon resonance assay the negative effects were demonstrated by the considerable increase of binding affinities of de-N-glycosylated S1 proteins produced from three different expression systems including baculovirus-insect, Chinese hamster ovarian and two variants of human embryonic kidney 293 cells. Molecular dynamic simulations of the S1 protein-ACE2 receptor complex revealed the steric hinderance and Coulombic repulsion effects of the different types of N-glycans on the S1 protein interaction with ACE2. The results presented here should contribute to future pathological studies of SARS-CoV-2 and therapeutic development of Covid-19, particularly using recombinant S1 proteins as models.Funding Information: The authors declare that they have no conflict of interest.Declaration of Interests: The work was supported in part by the National Natural Science Foundation of China (31600650, 31671369, and 62072435), the March of Dimes Prematurity Research Center grant (22-FY18-82), and Wellcome Trust Biomedical Resource grant (218304/Z/19/Z).