Dr. Patrick Drücker preseted at the Membrane Lipids Conference in Berlin

Patrick Drücker [1,2], Ioan Iacovache [2], Simon Bachler [1], Benoît Zuber [2], Eduard B. Babiychuk [2], Petra S. Dittrich [1], Annette Draeger [2]

[1] ETH Zürich, 4058 Basel, Switzerland
[2] University of Bern, 3012 Bern, Switzerland

Protein-membrane interactions that modify the shape of membranes are important for many biological processes by influencing curvature, membrane crowding or trafficking of vesicles. Giant vesicles represent a simplified but versatile model for biomembranes and are commonly employed for the study of phase segregation and permeation across compartments. Perforation of membranes by pore-forming toxins is a key factor during the cellular attack of pathogenic bacteria. The toxin pneumolysin (PLY) is secreted by Streptococcus pneumonia, which can cause severe pneumonia or meningitis in humans. Although the mechanism of pore formation is well understood, only little is known about PLY-induced membrane deformations. By employing unilamellar and multilamellar membrane models we discovered a hitherto undescribed layer-by-layer peeling mechanism that reveals membrane lamellarity and demonstrates a yet unknown mode of action of PLY disintegrating artificial multilamellar membranes. Using microfluidic methods to immobilize giant vesicles we demonstrate that this toxin can deform and enlarge bilayer membranes and suggest a potential mechanism based on protein-membrane and protein-protein aggregation.