Structural determinants of the scorpion venom peptide Uy234 reveal a membrane-disruptive mechanism in bacterial ESKAPE pathogens

Summary

The expansion-inhibiting impact of the peptide Uy234, current within the venom of the scorpion Urodacus yaschenkoi, has been investigated in two bacterial pathogens: Staphylococcus aureus ATCC 25923 and Acinetobacter baumannii AE12, the latter being a multidrug-resistant scientific isolate. As well as, its interplay with phospholipid bilayers has been studied utilizing atomic drive microscopy (AFM), permeability research in GUVs, and molecular dynamics simulations. To this finish, two inactivated variants of this peptide had been analyzed: Uy234-C (non-amidated peptide) and Uy234-A (P9A mutant). Solely the native peptide Uy234 exhibited bacteriostatic and bactericidal exercise, whereas each variants misplaced this antimicrobial exercise, highlighting the important function of the C-terminal amidation and the proline residue at place 9. In each instances, there may be proof of the important thing impact that these two structural determinants have on the bioactivity of Uy234 in opposition to the 2 pathogens. Along with quantifying intimately the minimal inhibitory and bactericidal concentrations for every microorganism, our research supplies clear proof of a membrane-damaging impact by means of bacterial cell viability assays with SYTO9/PI fluorophores. Notably, in SYTO9/PI assays carried out with S. aureus, membrane injury was detected solely within the presence of the native peptide Uy234, whereas no membrane disruption was noticed for the P9A mutant or the non-amidated variant. Furthermore, AFM imaging of supported POPE:POPG lipid bilayers revealed membrane thinning and lateral enlargement upon interplay with Uy234 , whereas our research with DOPC, POPC, and POPE:POPG GUVs point out dose-dependent permeabilization results for these mannequin methods in response to interplay with this peptide. In distinction, the mutant peptide P9A is unable to permeabilize GUVs, which is in line with the persistence of a better diploma of structural order for this mutant peptide, in keeping with molecular dynamics simulations within the aqueous section. These findings are in line with a membrane-disruptive mechanism doubtlessly involving peptide aggregation and transient pore formation for Uy234, making it an fascinating therapeutic various in opposition to multidrug-resistant micro organism.

Villa-Merlan, A. Ok., Mescola, A., Alejandro, P., Fernandez-Sánchez, F., Alessandrini, A., Balleza, D., & Quintero-Hernández, V. Structural determinants of the scorpion venom peptide Uy234 reveal a membrane-disruptive mechanism in bacterial ESKAPE pathogens. Frontiers in Microbiology, 17, 1830314. https://doi.org/10.3389/fmicb.2026.1830314