A group of Univ. of Southampton has investigated the effects of ACE2 glycan modification on the binding of S-protein of the new coronavirus (SARS-CoV-2) onto its infection receptor ACE2 .
https://www.sciencedirect.com/science/article/pii/S0022283620306872?via%3Dihub
By adding ST6 to WT ACE2 to increase sialic acid,
By adding Sialidase to WT ACE2 to cleave sialic acid,
By adding Kinfunensine to WT ACE2 to modify the glycan structure to Man9GlcNAc2 mainly,
By adding EndoH to WT ACE2 to remove N-type sugar chains,
By adding Fucosidase to WT ACE to remove Fuc,
and the binding of S-protein to ACE2 (Kd value) was measured by SPR.
When the N-glycans are removed from ACE2, the binding force is slightly increased, but the effect is limited.
Fuc modification of ACE2 has little effect.
Sialic acid modification of ACE2 does not seem to affect the infectivity, rather weaken the infectivity.
High mannose modification on ACE2 seems to weaken the infectivity slightly.