Rational design of a hybrid peptide against severe acute respiratory syndrome coronavirus 2 using melittin and angiotensin-converting enzyme 2 as pharmaceutical agents

Management of severe acute respiratory syndrome coronavirus 2 in humans depends on the availability of vaccines or effective drugs. Studies have shown that angiotensin‑converting enzyme 2 (ACE2) is responsible for binding the viral spike glycoproteins to human cells. Melittin from the bee venom of Apis melifera is a peptide with antimicrobial activities.

In this study, important amino acid residues of ACE2 interacting with spike glycoproteins of the virus were described based on the ACE2‑spike–glycoprotein interface. This has been previously analyzed by Robson in crystal structures of the receptors and ligands. Flexible linkers and 31 amino acid residues from N‑terminal of ACE2 as coronavirus spike binding domains (SBDs) were added to 17 N‑terminal amino acids of melittin (the hydrophobic motif) to construct a hybrid peptide or M‑ACE2SBD. Then, secondary and tertiary structures of the peptide were predicted.

Docking of the hybrid peptide and coronavirus SBDs was carried out as well. Previous studies showed that toxicity and hemolytic activity of the melittin hydrophobic motif decreased in comparison to native melittin due to the lack of peptide binding to the exposed anionic lipids of the human cell membranes and hence the novel peptide can be recommended as an appropriate drug for clinical uses.

This study has hypothesized that 17 N‑terminal amino acids of the mutant melittin used in M‑ACE2SBD design are potentially hydrophobic and attached coronavirus‑2 through lipid envelope of the virus.