Role of Cationic Group Structure in Membrane Binding and Disruption by Amphiphilic Copolymers Edmund F. Palermo Dong-Kuk Lee Ayyalusamy Ramamoorthy Kenichi Kuroda 10.1021/jp1083357.s001 https://acs.figshare.com/articles/journal_contribution/Role_of_Cationic_Group_Structure_in_Membrane_Binding_and_Disruption_by_Amphiphilic_Copolymers/2697637 Cationic, amphiphilic polymers are currently being used as antimicrobial agents that disrupt biomembranes, although their mechanisms remain poorly understood. Herein, membrane association and disruption by amphiphilic polymers bearing primary, tertiary, or quaternary ammonium salt groups reveal the role of cationic group structure in the polymer−membrane interaction. The dissociation constants of polymers to liposomes of POPC were obtained by a fluorometric assay, exploiting the environmental sensitivity of dansyl moieties in the polymer end groups. Dye leakage from liposomes and solid-state NMR provided further insights into the polymer-induced membrane disruption. Interestingly, the polymers with primary amine groups induced reorganization of the bilayer structure to align lipid headgroups perpendicular to the membrane. The results showed that polymers bearing primary amines exceed the tertiary and quaternary ammonium counterparts in membrane binding and disrupting abilities. This is likely due to enhanced complexation of primary amines to the phosphate groups in the lipids, through a combination of hydrogen bonding and electrostatic interactions. 2011-01-20 00:00:00 POPC Cationic Group Structure polymer end groups quaternary ammonium salt groups membrane quaternary ammonium counterparts NMR cationic group structure amphiphilic polymers