Structural- and Site-Specific <i>N-</i>Glycosylation Characterization of COVID-19 Virus Spike with StrucGP

The spike (S) protein plays a key role in COVID-19 (SARS-CoV-2) infection and host-cell entry. Previous studies have systematically analyzed site-specific glycan compositions as well as many important structural motifs of the S protein. Here, we further provide structural-clear N-glycosylation of the S protein at a site-specific level by using our recently developed structural- and site-specific N-glycoproteomics sequencing algorithm, StrucGP. In addition to the common N-glycans as detected in previous studies, many uncommon glycosylation structures such as LacdiNAc structures, Lewis structures, Mannose 6-phosphate (M6P) residues, and bisected core structures were unambiguously mapped at a total of 20 glycosites in the S protein trimer and protomer. These data further support the glycosylation structural–functional investigations of the COVID-19 virus spike.刺突（S）蛋白在新型冠状病毒肺炎（COVID-19，即SARS-CoV-2）的感染过程与宿主细胞入侵中发挥关键作用。既往研究已对S蛋白的位点特异性聚糖组成以及诸多关键结构基序开展了系统性分析。本研究依托课题组新近开发的结构与位点特异性N-糖蛋白质组学测序算法StrucGP，在位点特异性层面解析了结构明确的S蛋白N-糖基化修饰。除既往研究已检测到的常见N-聚糖外，本研究还在S蛋白三聚体与原聚体的总计20个糖基化位点上，明确鉴定到诸多罕见糖基化结构，包括LacdiNAc结构、Lewis结构、6-磷酸甘露糖（Mannose 6-phosphate, M6P）残基以及平分型核心糖结构。本数据集可为新冠病毒刺突蛋白糖基化的结构-功能研究提供进一步支撑。