Fortunately, however, the reflectivity results for the different peptide species 5, 7, and 8 need not be judged alone to make conclusions about the peptide orientation Fig. 11 Exemplary schematic representation of orientations that could be adopted by labeled peptide species in lipid multilayers and fit the reflectivity data of one or the other peptide species (Fig. 11) . The observed changes of the inner hydrophobic core upon peptide insertion, as revealed by GID/reciprocal space mapping, together with the sum of the reflectivity results may not completely rule out a simple surface anchoring or surface adhesion of the peptide species 2-9, but they make an inserted orientation parallel to the membrane normal, possibly with some tilt distribution, much more likely. This would be further supported by band shifts of the fluorescence emission spectra , indicating a localization of flanking tryptophan residues in the lipid headgroup regions.