Temporin G, an amphibian antimicrobial peptide against influenza and parainfluenza respiratory viruses: Insights into biological activity and mechanism of action

Treatment of respiratory viral infections remains a global health concern, mainly due to the inefficacy available drugs. Therefore, discovery novel antiviral compounds is needed; in this context, antimicrobial peptides (AMPs) like temporins hold great promise. Here, we discovered that harmless temporin G (TG) significantly inhibited early life-cycle phases influenza virus. The vitro hemagglutinating test revealed existence TG interaction with hemagglutinin (HA) protein. Furthermore, hemolysis inhibition assay and molecular docking studies confirmed TG/HA complex formation at level conserved hydrophobic stem groove HA. Remarkably, these findings highlight ability block conformational rearrangements HA2 subunit, which are essential for envelope fusion intracellular endocytic vesicles, thereby neutralizing virus entry into host cell. In comparison, case parainfluenza virus, penetrates cells upon membrane-fusion process, addition infected provoked ~1.2 log reduction titer released supernatant. Nevertheless, same condition, an immunofluorescent showed expression hemagglutinin/neuraminidase protein was not reduced. This suggested peptide-mediated some late steps replication therefore impairment extracellular release particles. Overall, our results first demonstration AMP interfere viruses different mechanism cell will open new avenue development therapeutic approaches against large variety viruses, including recent SARS-CoV2.