Seminar

Killing bacteria - the power of natural antibiotics

Kornelius Zeth, PhD

Uni- and multicellular organisms have developed smart methods to combat and kill bacteria. Many bacteria secret bacteriocins or proteins of the Cdi system to target and kill related or unrelated bacterial strains of the same culture, respectively. These narrow or broad band antibiotics typically comprise entire proteins, which unselectively destroy cellular components such as DNA, RNA, Peptidoglycane of they can permeabilize the inner membrane to disrupt the inner membrane potential. In mammalian, protection against bacterial or funghal treatment is induced by the production of antimicrobial peptides (AMPs). This battery of defense peptides can compromise the integrity of microbial cell membranes and thereby evade pathways by which bacteria develop rapid antibiotic resistance through mutations. Although more than 2000 host defense peptides from diverse origin have been described, the structural and mechanistic basis of their activity remains largely unknown. In order to understand the mechanism by which AMPs can compromise cell membranes we performed structure biology, electrophysiology, and MD simulations on one example, the human dermcidin (DCD) in membranes. This talk aims to give a glimpse on the targeting mechanisms of natural antibiotics. and points of bacterial membranes as a unique target for antibiotic attack.