Taking into consideration these factors contributing to NOE signals, we can conclude that peptide 15c with continuous NOE contacts between H N backbone atoms of Arg1-Arg2 and arg4-dip5 has more structured backbone than p3 (which has a single NOE contact between H N backbone atoms of Arg1-Arg2 only) and p1 (which shows no NOE contacts between H N backbone atoms detected in water). Therefore, we can hypothesize that in water, both 15c and p3 adopts preferred, highly populated conformations with restricted backbone mobility, whereas p1 lacks a defined conformation or its major conformation does not sufficiently constrain the orientation of the aromatic side chains, likely due to its non-systematic aggregation. Furthermore, as shown by the extended networks of cross-peaks in the NOESY spectra (Figure ), the structures of p3 and 15c become even more stabilized upon interaction with bacterial membrane-mimic lipids, while this stabilization is not observed with mammalian membrane-mimics.