Effects of membrane bilayer reorganizations on the 2103 cm⁻¹ Raman spectral CD stretching mode linewidths in dimyristoyl phosphatidylcholine‐d₅₄ (DMPC‐d₅₄) liposomes

The sensitivity of the bandwidths of the 2103 cm −1 symmetric methylene CD 2 stretching modes to lateral chain‐chain interactions and to intrachain rotamer formation is demonstrated for membrane bilayer systems composed of deuterated phospholipids. Temperature profiles, constructed from three separate linewidth parameters, illustrate the effects of bilayer rearrangements both in pure DMPC‐ d 54 liposomes and in DMPC‐ d 54 multilayers containing melittin in a lipid:polypeptide mole ratio of 14:1. Evidence is presented for a class of immobilized deuterated boundary lipids surrounding the polypeptide.