Site-specific N-glycosylation Characterization of Recombinant SARS-CoV-2 Spike Proteins using High-Resolution Mass Spectrometry

Yong Zhang; Wanjun Zhao; Yonghong Mao; Shisheng Wang; Yi Zhong; Tao Su; Meng Gong; Xiaofeng Lu; Jingqiu Cheng; Hao Yang

RBD has been demonstrated to induce potent and long-term immunity in animal models(40). Meanwhile, the subunit vaccines are posited to minimize the potentially undesired immunopotentiation of the full-length S protein, which might induce severe acute injury in the lungs(41). Intriguingly, SARS-CoV-2 is missing one N-glycosite in RBD compared to SARS-CoV. The remaining two N-glycosites were outside of the motifs essential for direct interaction with the ACE2 receptor(11) (Fig. 2C) . The glycan compositions of RBD are highly identical in the same host cell, regardless of the length of the RBD-containing proteins (Fig. 4B-4E ). These features of the RBD, along with its highly exposed structure, endow more antigens and accessible epitopes for vaccine design and immune recognition. The RBD-containing proteins, especially the insect cell-expressed products, could become promising candidates for SARS-CoV-2 vaccine development. However, drug discovery related to glycosylation inhibition is supposed to be performed based on human cell-expressed products.