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 gramicidin A transmembrane motifs. X-ray reflectivity measurements are performed on solid-supported peptide-lipid complexes to obtain information about the influence of the artificial dodecamer peptide on the bilayer parameters. In addition, Fourier-transform infrared (FTIR) and circular dichroism (CD) spectroscopic studies determine the conformational state of H-(Phe-Tyr)(5)-Trp-Trp-OH within the model membrane. Site-specific iodine labeling assists in determining the topology of the membrane-embedded peptide by pinpointing the position of the iodine label within the bilayers.
Küsel
Andrea
A
Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstr. 2, 37077 Göttingen, Germany.
Khattari
Ziad
Z
Schneggenburger
Philipp E
PE
Banerjee
Arnab
A
Salditt
Tim
T
Diederichsen
Ulf
U
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D008051:Lipid Bilayers / Q000737:chemistry*; D009842:Oligopeptides / Q000737:chemistry*; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared
D008051:Lipid Bilayers; D009842:Oligopeptides