Oriented circular dichroism of a class A amphipathic helix in aligned phospholipid multilayers.
The effect of lipid phase state on the orientation and conformation of a class A alpha-helical peptide on aligned lipid multilayers was examined using oriented circular dichroism spectroscopy. A comparison of oriented spectra in aligned peptide-lipid multilayers with CD spectra of unaligned peptide lipid vesicle complexes is consistent with a preferential alignment of helices parallel to the membrane surface at temperatures above and below the main acyl-chain melting transition temperature of the phospholipid. Changes are observed in the oriented CD spectra with lipid phase state which are attributed to a subtle conformational change of the peptide on the lipid surface. The results are compared with available experimental data on membrane-active lytic and antimicrobial helical peptides.
The Russell Grimwade School of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, Vic., Australia.
A H
AH
Clayton
W H
WH
Sawyer
D000595:Amino Acid Sequence; D002942:Circular Dichroism; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008567:Membranes, Artificial; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D010743:Phospholipids / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013696:Temperature
D008567:Membranes, Artificial; D010455:Peptides; D010743:Phospholipids; C080383:peptide 18A; D004134:Dimyristoylphosphatidylcholine