How the Antimicrobial Peptides Kill Bacteria: Computational Physics Insights

In the present article, coarse grained Dissipative Particle Dynamics simula- tion with implementation of electrostatic interactions isdeveloped in constant pressure and surface tension ensemble to elucidate how the antimicrobial peptide molecules af- fect bilayer cell membrane structure and kill bacteria. Wefind that peptides with differ- ent chemical-physical properties exhibit different membrane obstructing mechanisms. Peptide molecules can destroy vital functions of the affected bacteria by translocat- ing across their membranes via worm-holes, or by associating with membrane lipids to form hydrophilic cores trapped inside the hydrophobic domain of the membranes. In the latter model, the affected membranes are strongly buckled, in accord with very recent experimental observations (G. E. Fantner et al., Nat. Nanotech., 5 (2010),pp. 280- 285).