Stapled peptides as potential inhibitors of SARS-CoV-2 binding to the hACE2 receptor

Stapled peptides are synthetic peptidomimetics of bioactive sites in folded proteins which carry chemical links, introduced during peptide synthesis, designed to retain the secondary structure in the native protein molecule. Stapled peptides have been investigated as potential modulators of protein-protein interactions for over two decades. The potential use of stapled peptides as inhibitors of viral entry, and therefore as antiviral therapeutics, has been established for several important viruses causing disease in humans, such as the human immunodeficiency virus type 1 (HIV-1), respiratory syncytial virus (RSV), and Middle East Respiratory Syndrome (MERS) coronavirus. Several independent research initiatives have investigated the inhibitory effect of stapled peptides on binding of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, to its receptor, angiotensin-converting-enzyme 2 (ACE2). These stapled peptides, which mimic Helix 1 of the human ACE2 receptor, have demonstrated mixed ability to prevent infection with SARS-CoV-2 in cell-based studies.