Structure-Guided Design of Temporin-Derived Peptides Reveals Potent Dual-Mechanism Inhibitors of SARS-CoV‑2

The study investigates temporin-derived antimicrobial
peptides
as broad-spectrum antiviral candidates against SARS-CoV-2. Surface
plasmon resonance screening shows that temporin G (TG), temporin L (TL), and the nonhemolytic analog Pro3-TL bind the trimeric
Spike protein with high affinity, following a two-state binding model.
NMR confirms TG–Spike interactions and identifies
Phe2 as critical for binding. Docking simulations place
the interaction at the NTD–RBD interface and reveal a cation−π
interaction between TG Phe2 and Spike Arg357. These insights informed the design of the chimeric analog RB-142 and four derivatives (RB-143 to RB-146) incorporating bulkier aromatic residues. All analogs
exhibit submicromolar binding affinities. Biological assays show low
cytotoxicity and potent virucidal activity, with RB-146 demonstrating the strongest effect and a high therapeutic index.
Mechanistic analyses indicate that RB-146 disrupts viral
attachment and damages the viral envelope. The findings position RB-146 as a promising dual-mechanism antiviral candidate.