Identification of SARS-CoV-2-binding lectins on a commercial lectin array.

The Spike glycoprotein of SARS-CoV-2 is the major target for vaccines and therapeutics. Spike glycosylation is critical for ACE2 binding and subsequent viral fusion and entry. Here, we studied lectins for their ability to bind to SARS-CoV-2 Spike glycoprotein and SARS-CoV-2 virions by employing an array of 95 lectins, for 68 of which we predicted glycan-binding specificities using publically available glycan array data and MotifFinder software. We identified lectins with diverse glycan binding specificities that bound with high intensities to recombinant Spike and cultured SARS-CoV-2 virus - AAL, ABL, ACL, AMA, ASA, BANLEC, BC2L-A, RCA 120, CALSEPA, GAL3, GS-II, PALa, CA, HHA, PHA-L, PA-IIL, MNA-M, STL, LSL-N, GRFT, PSA, RS-FUC, PHA-E, CPA, LENTIL, RCA 60, GNA, ORYSATA, LcH A, PHA-P, PTL-2, MAA, Con A, TL, NPA, and SBA. Analyzing the glycan-binding specificities of these lectins, we predict that the Spike glycoprotein is modified with high mannose/hybrid N-glycans with terminal mannose residues, α1-6 core fucosylated N-glycans with terminal GlcNAc residues, and complex glycans with Lewis A, Lewis B, Lewis X, Lewis Y, and Blood group H structures on type-1 or type-2 extension sequences. The SARS-CoV-2-specific lectins identified in our study may be assessed for their antiviral potential in future studies.