title: Magainin 2 induces bacterial cell death showing apoptotic properties.
abstract: Magainin 2 is pore-forming antimicrobial peptide on lipid matrix of bacterial membrane, secreted from the skin of the African clawed frog Xenopus laevis. The aim of this study was to investigate a new concept for antibacterial mechanisms called bacterial apoptosis-like cell death. We examined the morphological changes induced by magainin 2 in Escherichia coli, regarding apoptosis. Specifically, phosphatidylserine externalization from the inner to outer membrane surface was detected by Annexin V staining, and DNA fragmentation and chromatin condensation was detected by TUNEL and DAPI assay. We also found much mechanistic evidence to support the hypothesis that magainin 2 induces bacterial apoptosis-like death-including disturbance of membrane detected by DiBAC4(3), caspase activation observed by FITC-VAD-FMK staining, and analyzing the role of RecA in bacterial apoptosis-like death through the RecA expression assay by Western blot-in E. Coli when treated with magainin 2. On the basis of these results, magainin 2 exerts antibacterial activity with a new mechanism which is bacterial apoptosis-like death. Searching antimicrobial agents with novel mechanisms of action can be an effective strategy to coping with the emergence of new resistance mechanisms. Magainin 2 deserves further research as a potential antimicrobial therapeutic agent.
authors.affiliation: School of Life Sciences, BK 21 Plus KNU Creative BioResearch Group, College of Natural Sciences, Kyungpook National University, Daehak-ro 80, Buk-gu, Daegu, 702-701, Republic of Korea.
authors.forename: Wonyoung
authors.initials: W
authors.lastname: Lee
authors.forename: Dong Gun
authors.initials: DG
authors.lastname: Lee
mesh_terms: D017304:Annexin A5; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D017209:Apoptosis; D053938:DNA Fragmentation / Q000187:drug effects; D004926:Escherichia coli / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology; D020287:In Situ Nick-End Labeling; D007211:Indoles; D054806:Magainins / Q000494:pharmacology*; D050296:Microbial Viability / Q000187:drug effects*; D010718:Phosphatidylserines / Q000032:analysis; D029867:Xenopus Proteins / Q000494:pharmacology*
chemical_list: D017304:Annexin A5; D000900:Anti-Bacterial Agents; D007211:Indoles; D054806:Magainins; D010718:Phosphatidylserines; D029867:Xenopus Proteins; C053301:magainin 2 peptide, Xenopus; C007293:DAPI