Conformation and interaction of a D,L-alternating peptide with a bilayer membrane:: X-ray reflectivity, CD, and FTIR spectroscopy

Peptides with alternating amino acid configuration provide helical secondary structures that are especially known from the membrane channel and pore-forming gramicidin A. In analogy to this natural D,L-alternating pentadecapeptide, the potential of D,L-alternating peptides for membrane insertion is investigated using the model dodecamer peptide H-(Phe-Tyr)(5)-Trp-Trp-OH.\ This aromatic peptide is introduced as a novel pore-forming synthetic analogue of gramicidin A. It forms a well-organized homodimer similar to one of the gromicidin A transmembrane motifs.