Engineering myxinidin-based supramolecular architectures for advanced antifungal applications in food protection

The antimicrobial peptide WMR-4, a myxinidin-derived sequence with Aib and D-amino acid substitutions, showed enhanced stability and strong antifungal activity against Fusarium oxysporum in vitro. Biophysical studies indicated a lytic mechanism via deep membrane insertion and leakage. However, free WMR-4 failed to block fungal penetration through cellulose barriers, revealing limits in complex systems. To overcome this, we developed supramolecular nanofibers functionalized with WMR-4 and the cell-penetrating peptide gH625. These nanofibers inhibited germ tube formation, partially reduced cellulose membrane penetration, and provided enhanced protection in biological contexts. Specifically, nanofibers limited opportunistic saprophytic colonization in apple tissues lacking epidermal barriers while preserving tissue integrity in intact tomato models, demonstrating barrier-specific therapeutic protection. SEM and AFM confirmed stable nanoscale coatings integrated into plant epidermal layers. These results highlight WMR-4 as a potent antifungal candidate and demonstrate the potential of AMP-functionalized supramolecular nanostructures for agricultural applications.