Formation of pre-pore complexes of pneumolysin is accompanied by a decrease in short-range order of lipid molecules throughout vesicle bilayers.

ABSTRACT: Oligomers of pneumolysin form transmembrane channels in cholesterol-containing lipid bilayers. The mechanism of pore formation involves a multistage process in which the protein, at first, assembles into a ring-shaped complex on the outer-bilayer leaflet. In a subsequent step, the complex inserts into the membrane. Contrary to most investigations of pore formation that have focussed on protein changes, we have deduced how the lipid-packing order is altered in different stages of the pore-forming mechanism. An optical tweezing apparatus was used, in combination with microfluidics, to isolate large-unilamellar vesicles and control exposure of the bilayer to pneumolysin. By monitoring Raman-scattered light from a single-trapped liposome, the effect of the protein on short-range order and rota

SUBMITTER: Faraj BHA 

PROVIDER: S-EPMC7067851 | biostudies-literature | 2020 Mar

REPOSITORIES: biostudies-literature