Paper BI+AS+BA+NS+SS-ThA3
Nanoscale Imaging of Peptide-Membrane Interactions

Thursday, October 31, 2013, 2:40 pm, Room 102 B

Antimicrobial peptides (AMPs) are attracting growing attention as efficient anti-infective agents in the post-antibiotic era. However, the detailed molecular mechanisms of their action and precise rationale for their selectivity remain poorly understood.

Here we will present our recent findings, highlighting specific membrane-mediated mechanisms of AMPs, which we probed using a de novo designed archetypal AMP and imaged using a combination of Atomic Force Microscopy (AFM) and high-resolution Secondary Ion Mass Spectrometry (NanoSIMS). This approach provides unique information on the topography of peptide-treated membranes, obtained from AFM images, suggesting membrane changes as a result of peptide structuring and pore formation. The data is complemented by chemical imaging performed on the same samples with NanoSIMS, which revealed the precise localization of peptide molecules in the membranes.

This comparative topographical and chemical imaging gives the first evidence of antimicrobial pore expansion that was further strengthened by AFM imaging in real time in liquid, and supported by microbiological and biophysical studies as well as molecular dynamic simulations.

Relevant publication:

Rakowska, P. D., Jiang, H., Ray, S., et al. Nanoscale imaging reveals laterally expanding antimicrobial pores in lipid bilayers. Proc. Natl. Acad. Sci. USA, 2013, 110, in press.