A 3D structure of the S trimer was generated by using a homology model of the S trimer described previously (based on PDB: 6VSB; Wrapp et al., 2020). Onto this 3D structure, we installed explicitly defined glycans at each glycosylated sequon based on one of three separate sets of criteria, thereby generating three different glycoform models for comparison that we denote as “Abundance,” “Oxford Class,” and “Processed” models (STAR Methods; Table S1). These criteria were chosen in order to generate glycoform models that represent reasonable expectations for glycosylation microheterogeneity and integrate cross-validating glycomic and glycoproteomic characterization of S and ACE2.