Orientations of amphipathic helical peptides in membrane bilayers determined by solid-state NMR spectroscopy.
Solid-state NMR spectroscopy was used to determine the orientations of two amphipathic helical peptides associated with lipid bilayers. A single spectral parameter provides sufficient orientational information for these peptides, which are known, from other methods, to be helical. The orientations of the peptides were determined using the 15N chemical shift observed for specifically labeled peptide sites. Magainin, an antibiotic peptide from frog skin, was found to lie in the plane of the bilayer. M2 delta, a helical segment of the nicotinic acetylcholine receptor, was found to span the membrane, perpendicular to the plane of the bilayer. These findings have important implications for the mechanisms of biological functions of these peptides.
Bechinger
B
B
Department of Chemistry, University of Pennsylvania, Philadelphia 19104.
Kim
Y
Y
Chirlian
L E
LE
Gesell
J
J
Neumann
J M
JM
Montal
M
M
Tomich
J
J
Zasloff
M
M
Opella
S J
SJ
D000595:Amino Acid Sequence; D023181:Antimicrobial Cationic Peptides; D007473:Ion Channels / Q000737:chemistry*; D008051:Lipid Bilayers / Q000737:chemistry*; D054806:Magainins; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008563:Membrane Lipids / Q000737:chemistry; D008565:Membrane Proteins / Q000737:chemistry*; D008968:Molecular Conformation; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D011978:Receptors, Nicotinic / Q000737:chemistry*; D029867:Xenopus Proteins
D023181:Antimicrobial Cationic Peptides; D007473:Ion Channels; D008051:Lipid Bilayers; D054806:Magainins; D008563:Membrane Lipids; D008565:Membrane Proteins; D010446:Peptide Fragments; D010455:Peptides; D011978:Receptors, Nicotinic; D029867:Xenopus Proteins; C053301:magainin 2 peptide, Xenopus