Venom peptides as selective inhibitors of bacterial ATP synthase

Abstract

BackgroundIt is predicted that by the year 2050 world will face 10 million additional deaths per year due to antibiotic resistance. Misuse and overuse of antibiotics, is making microbes resistant to normally effective antibiotics. Therefore, it is of necessary to find different ways to combat microbial infections. ATP synthase is the main source of cellular energy production in almost all organisms from bacteria to men. Selective inhibition of bacterial ATP synthase to kill bacteria provides an effective way to eradicate antibiotic resistant bacteria. Venom peptides from many sources bind and inhibit ATP synthase. Venom peptides bind at the βDELSEED‐motif of ATP synthase. Although βDELSEED‐motif is highly conserved throughout the evolution but is skirted by more than twenty variable amino acids. We are identifying and characterizing the selective venom peptide inhibitors of ATP synthase using Escherichia coli as a model organism.MethodWild type, null, and mutant E. coli strains are used to select the strong venom peptide inhibitors of ATP synthase. Growth of E. coli strains is measured on fermentable and non‐fermentable carbon sources in presence and absence of venom peptides. F1Fo ATP synthase is isolated by harvesting cells in the minimal media, lysing cells by French Press, and isolating membrane bound ATP synthase by multiple high‐speed ultracentrifugation. A variety of venom peptides are used to inhibit ATP synthase. Inhibitory potency of venom peptides is augmented by incremental addition of charge and α helicity.ResultsVenom peptides cause variable degree of ATP synthase inhibition. Modifications of venom peptides cause increased inhibition. Addition of a c‐terminal NH2 group in venom peptides augment the inhibitory effects by about 100‐fold. Venom peptides also show synergistic inhibitory effects on ATP synthase.ConclusionsVenom peptides potently kill E. coli cells by binding at βDELSEED‐motif of ATP synthase. ATP synthase can be used as a potent molecular drug target to combat antibiotic resistant bacterial infections.Support or Funding InformationWarner/Fermaturo and ATSU Board of Trustees Research Grant