Quantification of bilayer roughening.

Abstract

<p>(A) Quantitative assessment of bilayer disruption by analysis of root mean square (RMS) roughness of images taken before and after exposure to various Aβ (1–40) peptides is shown. Control corresponds to RMS roughness measurements taken on supported TBLE lipid bilayers that had not been exposed to any Aβ (1–40) peptides. Exposure to Wild Type, Arctic, Italian, Iowa, or Flemish Aβ (1–40) induced significant (* indicates p<0.01) roughening of the supported TBLE lipid bilayer. RMS roughness measurements of disrupted areas were restricted to areas that displayed enhanced roughness to prevent biased based on the extent of disruption. (B) The percent area of TBLE bilayers containing increased roughness induced by exposure to Wild Type, Arctic, Italian, Iowa, or Flemish Aβ (1–40) was measured from images obtained 10–12 hours after the initial injection of Aβ (1–40) peptides. Exposure to Arctic Aβ (1–40) resulted in a significantly larger area of the bilayer being disrupted in comparison to Wild Type (* indicates p<0.01). The extent of bilayer disruption was significantly reduced when bilayers were exposed to Iowa or Flemish Aβ (1–40) in comparison to Wild Type (** indicates p<0.05).</p