Figure 11.

Peptide-induced permeabilization of GUVs. Membrane leakage of Alexa Fluor 647 hydrazide (AF647) and membrane permeabilization of carboxyfluorescein (CF)-labeled magainin 2 (CF-magainin 2) is visualized in single 40%DOPG/60%DOPC-GUVs. (A) and (B) shows confocal laser scanning microscopy (CLSM) images of (1) AF647 and (2) CF-Magainin 2 in a single GUV treated with 31 μM CF-magainin 2/magainin 2 and 20 μM CF-magainin 2/magainin 2 respectively at certain time after of CF-magainin 2/magainin 2 addition to GUV denoted in seconds under each image. (C) and (D) describe the time course of peptide-induced decrease in fluorescence intensity of AF647 in the GUV and increase in permeation of CF in the rim of GUV following the addition of CF-magainin 2/magainin 2. The solid red line corresponds to fluorescence intensity of AF647 inside the GUV while the green triangles correspond to the fluorescence intensity of CF-magainin 2 in the rim. The circles correspond to the fluorescence intensity of the outside vicinity of the GUV. FI = I(t)/I(0), where I(t) and I(0) are the fluorescence intensity of AF647 inside the GUV at time = t. (E) refers to concentration dependent average lag time between the stochastic permeabilization of magainin 2 in to the GUV and the leakage of dye from inside the GUV. These two phenomena can be studied by quantification of increase in the fluorescence intensities of the CF at rim of the GUV and decrease in the fluorescence intensity of AF647 from inside the GUV. Adapted with permission from ref 358. Copyright 2015 American Chemical Society. Images courtesy of Masahito Yamazaki.