Lipid composition modulates membrane interaction of antimicrobial peptide colistin. A Langmuir monolayer study

Abstract

Colistin is an antimicrobial peptide used as a last-resort antibiotic. Understanding its interaction with cell membranes is crucial for elucidating its mechanism of action and for guiding the development of improved or novel antibiotics based on colistin derivatives. In this study, model membrane systems were employed to investigate how the composition of lipid mixtures, mimicking both prokaryotic and eukaryotic membranes, affects the interaction of colistin with lipid interfaces. Langmuir monolayer experiments, including simultaneous measurements of surface pressure and surface potential, as well as Brewster angle microscopy, revealed that colistin interacts preferentially with prokaryotic model membranes. Additionally, the lipid composition influenced the peptide's organization at the membrane interface, potentially contributing to the biological activity of colistin.