Figure 5.

SARS-CoV-2 spike proteins compete with complement factor H for the same binding sites on heparin. (A) The binding of complement factor H (CFH) to heparin-linked beads was markedly reduced in the presence of SARSCoV- 2 spike protein subunit 1 (S1) and subunit 2 (S2). The western blot was performed using anti-CFH antibody. (B) S1 and S2 retained similarly high binding affinity to heparin-linked beads in the presence and absence of CFH. The western blot was performed using anti-His antibody. The input is the protein solution that is used to incubate with the beads. S: SARS-CoV-2 spike protein; S1: SARSCoV- 2 spike protein subunit 1; S2: SARS-CoV-2 spike protein subunit 2.