PT  - JOURNAL ARTICLE
AU  - So Young Kim
AU  - Weihua Jin
AU  - Amika Sood
AU  - David W. Montgomery
AU  - Oliver C. Grant
AU  - Mark M. Fuster
AU  - Li Fu
AU  - Jonathan S. Dordick
AU  - Robert J. Woods
AU  - Fuming Zhang
AU  - Robert J. Linhardt
TI  - Glycosaminoglycan binding motif at S1/S2 proteolytic cleavage site on spike glycoprotein may facilitate novel coronavirus (SARS-CoV-2) host cell entry
AID  - 10.1101/2020.04.14.041459
DP  - 2020 Jan 01
TA  - bioRxiv
PG  - 2020.04.14.041459
4099  - http://biorxiv.org/content/early/2020/04/15/2020.04.14.041459.short
4100  - http://biorxiv.org/content/early/2020/04/15/2020.04.14.041459.full
AB  - Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has resulted in a pandemic and continues to spread around the globe at an unprecedented rate. To date, no effective therapeutic is available to fight its associated disease, COVID-19. Our discovery of a novel insertion of glycosaminoglycan (GAG)-binding motif at S1/S2 proteolytic cleavage site (681-686 (PRRARS)) and two other GAG-binding-like motifs within SARS-CoV-2 spike glycoprotein (SGP) led us to hypothesize that host cell surface GAGs might be involved in host cell entry of SARS-CoV-2. Using a surface plasmon resonance direct binding assay, we found that both monomeric and trimeric SARS-CoV-2 spike more tightly bind to immobilized heparin (KD = 40 pM and 73 pM, respectively) than the SARS-CoV and MERS-CoV SGPs (500 nM and 1 nM, respectively). In competitive binding studies, the IC50 of heparin, tri-sulfated non-anticoagulant heparan sulfate, and non-anticoagulant low molecular weight heparin against SARS-CoV-2 SGP binding to immobilized heparin were 0.056 μM, 0.12 μM, and 26.4 μM, respectively. Finally, unbiased computational ligand docking indicates that heparan sulfate interacts with the GAG-binding motif at the S1/S2 site on each monomer interface in the trimeric SARS-CoV-2 SGP, and at another site (453-459 (YRLFRKS)) when the receptor-binding domain is in an open conformation. Our study augments our knowledge in SARS-CoV-2 pathogenesis and advances carbohydrate-based COVID-19 therapeutic development.Competing Interest StatementThe authors have declared no competing interest.