title: Antimicrobial Peptides from the Aurein Family Form Ion-Selective Pores in Bacillus subtilis.
abstract: The mechanism of action of aurein 2.2 and aurein 2.3, antimicrobial peptides from the frog Litoria aurea, was investigated. Proteomic profiling of the Bacillus subtilis stress response indicates that the cell envelope is the main target for both aureins. Upon treatment, the cytoplasmic membrane depolarizes and cellular ATP levels decrease. Global element analysis shows that intracellular concentrations of certain metal ions (potassium, magnesium, iron, and manganese) strongly decrease. Selective translocation of some ions over others was demonstrated in vitro. The same set of ions also leaks from B. subtilis cells treated with sublethal concentrations of gramicidin S, MP196, and nisin. Aureins do not permeabilize the cell membrane for propidium iodide thus excluding formation of large, unspecific pores. Our data suggest that the aureins acts by forming small pores thereby causing membrane depolarization, and by triggering the release of certain metal ions thus disturbing cellular ion homeostasis.
authors.affiliation: Applied Microbiology, Ruhr University Bochum, Universitätsstrasse 150, 44801 Bochum (Germany).
authors.forename: Michaela
authors.initials: M
authors.lastname: Wenzel
authors.forename: Christoph Helmut Rudi
authors.initials: CH
authors.lastname: Senges
authors.forename: Jin
authors.initials: J
authors.lastname: Zhang
authors.forename: Selina
authors.initials: S
authors.lastname: Suleman
authors.forename: Michael
authors.initials: M
authors.lastname: Nguyen
authors.forename: Prashant
authors.initials: P
authors.lastname: Kumar
authors.forename: Alina Iulia
authors.initials: AI
authors.lastname: Chiriac
authors.forename: Jennifer Janina
authors.initials: JJ
authors.lastname: Stepanek
authors.forename: Nadja
authors.initials: N
authors.lastname: Raatschen
authors.forename: Caroline
authors.initials: C
authors.lastname: May
authors.forename: Ute
authors.initials: U
authors.lastname: Krämer
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Sahl
authors.forename: Suzana Katarina
authors.initials: SK
authors.lastname: Straus
authors.forename: Julia Elisabeth
authors.initials: JE
authors.lastname: Bandow
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D023181:Antimicrobial Cationic Peptides / Q000737:chemistry / Q000494:pharmacology*; D001001:Anura; D001412:Bacillus subtilis / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects; D006706:Homeostasis / Q000187:drug effects; D008969:Molecular Sequence Data; D016062:Porosity; D040901:Proteomics
chemical_list: D023181:Antimicrobial Cationic Peptides; C519956:aurein 2.2 peptide; C519957:aurein 2.3 peptide
keywords: antibiotics; antimicrobial peptides; membranes; metal ions; proteomics