Binding Ligands that Straddle an Important Contact Site on the RBD of the Covid-19 Spike Protein

The receptor binding domain (RBD) of the spike protein of the Covid-19 virus is responsible for attachment to human ACE2. A number of recent articles have studied monoclonal antibody blocking [8-11] and peptide inhibitors [12-16] of the Covid-19 virus. Here we report virtual ligand-based screening that targets pockets on each side of an important binding site with residues 502-504 on the RBD that contact residues 353-357 [15] of hACE2. These ligands are intended as pre-exposure therapy for Covid-19 infection.