Characterization of peptide-induced morphological alterations in membranes by fluorescence resonance energy transfer

Interaction of fusogenic or membrane-perturbing peptides with lipid bilayers often involves drastic rearrangements of the membrane structure, with redistribution of lipids, inducement of bilayer curvature, or formation of non-bilayer or multibilayer structures. Fluorescence (or Förster) Resonance Energy Transfer (FRET) is a photophysical technique which has an acute sensitivity to distances in the nanometer range, and, as such, is particularly suited to probe alterations in membrane organization in this length scale. This article reviews methods and selected applications of FRET in this field, from the now classic (fusion induced) lipid-mixing assay to examples where kinetic modeling of FRET enables the recovery of topological information.