Protection of SARS-CoV-2 Infection by Targeting Viral Spike Protein With De Novo Designed ACE2-Derived Undecapeptide.

The envelope-anchored trimeric spike protein of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mediates the attachment and entry of the virus within human cells by utilizing the angiotensin converting enzyme 2 (ACE2) as a receptor, present in the epithelial cells of the upper respiratory tract and lungs. The ACE2 interaction interface with the SARS-CoV-2 spike protein was utilized to design an ACE2-derived peptide sequence (FD11) that targeted the viral spike protein. It was found to be non-cell penetrating, while in vivo studies revealed the non-cytotoxic nature of the peptide molecule. The minimum effective concentration of the peptide was found to be 10 μM with 95% cell viability in Vero E6 cell line. The IC50 of the peptide was found to be around 6.4 μM. Treatment of the peptide in SARS-CoV-2 infected Vero E6 cells was found to decrease the infectivity as compared to control. This presents a simple approach where host-pathogen protein interaction-interface derived peptides can be used for binding with substrate macromolecules to target and modulate pathogen infectivity.