A connection between antimicrobial properties of venom peptides and microbial ATP synthase.

Venom peptides anoplin, cupiennin 1a, latarcin 1, latarcin 3a, latarcin 5, melittin, and pandinin 2 are known to have antibacterial properties. In the current study, we examined whether the antimicrobial properties of these venom peptides have any connection to the binding and inhibition of bacterial ATP synthase. Venom peptides inhibited Escherichia coli wild type and mutant membrane-bound F1Fo ATP synthase to varying degrees. Although significant loss of oxidative phosphorylation was observed for wild type, very little loss occurred for null and mutant E. coli strains in the presence of venom peptides. This study also reaffirms that βDELSEED-motif residues of ATP synthase are required for peptide binding. Modified venom peptides with C-terminal amide (NH2) groups caused augmented inhibition of ATP synthase and E. coli cell death. Growth patterns of wild type, null, and mutant strains in the presence of melittin, anoplin, cupiennin 1a, latarcin 1, latarcin 3a, latarcin 5, pandinin 2, and their modified variants suggested the possibility of additional molecular targets. Our results demonstrate that the antimicrobial properties of venom peptides are connected to the binding and inhibition of bacterial ATP synthase. Moreover, selective inhibition of ATP synthase by venom peptides suggests a viable alternative to combat antibiotic-resistant microbial infections.