PROS1 and viral infectious disease: Mutation of N90 residue increases the binding affinity to S protein,399 indicating N90 glycosylation can protect host cells against viral infection.400 Atomistic molecular dynamics (MD) simulations show that N322 glycan binds to the core region of RBD of S protein from amino acid 369 to 378.40,400 The interaction between RBD and N322 residue of ACE2 is much stronger than that between RBD and N90 residue of ACE2.