Vesicle Aggregation and Fusion Influence Membrane Permeabilization Induced by Antimicrobial Polycations

Synthetic polycations, such as nylon-3 copolymers, are regarded to be good functional mimics of antimicrobial peptides acting mostly by permeabilizing bacterial membranes. Understanding more complex membrane behavior behind permeabilization, e.g. vesicle aggregation and fusion, has major implications for the better interpretation different mechanisms actions. The interactions two types copolymers containing cationic/hydrophobic subunits with zwitterionic or negatively charged vesicles were evaluated. Cryo-electron microscopy visually shows behaviors (i.e. aggregation, fusion vesicles) after adding both copolymers. Fluorescence lifetime-based calcein leakage assay was used characterize various permeabilization. Even more, process detected lipid mixing (NBD-Rhodamine resonance energy transfer assay) content (ANTS-DPX Assay). Interestingly, relationship between permeabilization differs Both occur often when polycations AMPs their synthetic interact vesicles. role in is still unclear.