Supplementary file 1_The scorpion peptide Eval418 inhibits duck Tembusu virus replication by disrupting viral structure and early-stage infection.pdf

Time-of-addition, free virion, attachment, and entry/fusion assays were performed, along with transmission electron microscopy and molecular docking/MD simulations of the NS3-Eval418 complex.</p>Results<p>Eval418 inhibited DTMUV replication in a concentration-dependent manner, achieving over 99% inhibition at 10 μM, with no significant cytotoxicity or hemolytic activity up to 120 μM in all tested cells. Mechanistic studies revealed that Eval418 acted primarily during the coaddition stage by directly inactivating free virions, blocking viral attachment, and inhibiting viral entry/fusion.

TEM confirmed that Eval418 directly disrupted the morphological integrity of DTMUV virions, causing structural collapse. MD simulations showed that Eval418 binds stably to the NS3 binding pocket. Eval418 also inhibited two genetically distinct DTMUV isolates, whereas prolonged incubation with duck serum progressively reduced its antiviral activity.</p>Conclusion<p>These findings establish Eval418 as a promising lead compound for the development of antiviral therapeutics against DTMUV infection as a model flavivirus.

Its potential efficacy against other flaviviruses requires further investigation.</p>