Tetrafenyloporfirynowy copper complex ( CuTPP ) is associated with the lipid bilayer . Electron paramagnetic resonance spectra (ERP ) oriented films of liquid crystal dimyrystynowej phosphatidylcholine ( DMPC ) -containing CuTPP indicate that the content of ≤ 1 mol % CuTPP molecules CuTPP surface is perpendicular to a membrane surface , while the mol % Cl4 content of the surface is parallel to a membrane surface .