Structure-Guided Temporin L Analogs Development to Inhibit the Main Protease of SARS-CoV-2

Peptide-based inhibitors exhibit considerable potential as antiviral agents targeting SARS-CoV-2. In this study, we designed analogs (TLP-1, TLP-2, and TLP-3) of Temporin L (TL) peptide with the specific objective of selectively interacting with and targeting the main protease (Mpro) of SARS-CoV-2. The synthesis and characterization of TLPs were employed using solid-phase peptide synthesis and LC-MS respectively. CD and solution NMR spectroscopy elucidated the overall structure of the TLPs relative to TL, revealing folded peptides where introduced mutations alter the peptide conformation for binding to Mpro. MD simulations highlighted improvements in TLP's stability and interactions with Mpro. FRET based protease activity assays provided evidence that TLPs exhibited enhanced inhibitory activity against Mpro. The results of our study reveal the promising prospects of TLPs as attractive candidates for <i>in vivo</i> investigations, thereby contributing to the progress of peptide-based therapeutic approaches targeting SARS-CoV-2.