Resonance energy transfer study of peptide–lipid complexes Original Research Article

Resonance energy transfer involving tryptophan as a donor and anthrylvinyl-labeled phosphatidylcholine (AV-PC), 3-methoxybenzanthrone (MBA) and 8-anilino-1-naphthalene sulfonic acid (ANS) as acceptors has been examined to obtain information on the structure of peptide–lipid systems consisting of 18A or Ac-18A-NH2 peptides and large unilamellar phosphatidylcholine vesicles. The lower and upper limits for the tryptophan distance from the bilayer midplane have been assessed in terms of the models of energy transfer in two-dimensional systems, taking into account orientational effects. Evidence for the existence of preferential orientations of Ac-18A-NH2 with respect to the lipid–water interface has been obtained.