FIG 2.

K31 binds to SARS-CoV-2 N protein and inhibits virus replication in cells. (A) Biolayer interferometry showing the association and dissociation kinetics for the binding of K31 with C-terminally His-tagged N protein, immobilized on a Ni-NTA biosensor. The experiment was repeated at three different concentrations of K31 as shown. (B) Cytotoxicity of K31 on Caco2 cells. Caco2 cells in 96-well plates were treated with increasing concentrations of K31 for 3 days and examined for cytotoxicity using a CellTiter-Glo luminescent assay (see reference 17 for details). (C) Inhibition profile showing the percentage of SARS-CoV-2 replication in Caco2 cells at increasing concentrations of K31. SARS-CoV-2 replication was determined by quantification of viral genomic RNA using real-time PCR. (D) Western blot analysis showing N protein levels in SARS-CoV-2-infected Caco2 cells in the absence or presence of 10 μM K31.