A novel approach for selecting potent peptide inhibitors of the SARS-CoV2-Mpro protease

Here, we describe a new high throughput selection technology for identifying exceedingly specific and effective peptide inhibitors. This technology incorporates the co-expression of a cytotoxic protein and a library of peptide variants inserted directly into a loop of a carrier protein. Selection is based on the cytotoxicity neutralization by a member of a peptide library binding to and inhibiting the cytotoxic protein. Our technology provides the flexibility of screening both cyclic and linear peptides. Herein, we demonstrate the power of this technology by developing selective inhibitors of the main coronavirus protease (Mpro) in a matter of weeks by screening libraries of cyclic and linear peptides. This technology opens up an opportunity to develop inhibitors for a wide range of previously undruggable targets.