Transmembrane model peptides enable the investigation of complex protein-lipid interactions since the specific structure of proteins is influenced by the lipid environment. Herein, the synthesis of nitroxide spin labels for transmembrane peptides is present and PEDLOR nanometer distance measurements are discussed. It was demonstrated that the combination of semi-rigid labels with high-power pulsed EPR allows straightforward structural interpretation of the observed distances in solution and lipid bilayer. In particular, the labels deliver reliable distances and sharp distance distributions even in the lipid bilayer.
