Molecular organization in striated domains induced by transmembrane alpha-helical peptides in dipalmitoyl phosphatidylcholine bilayers.
Transmembrane (TM) alpha-helical peptides with neutral flanking residues such as tryptophan form highly ordered striated domains when incorporated in gel-state 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) bilayers and inspected by atomic force microscopy (AFM) (1). In this study, we analyze the molecular organization of these striated domains using AFM, photo-cross-linking, fluorescence spectroscopy, nuclear magnetic resonance (NMR), and X-ray diffraction techniques on different functionalized TM peptides. The results demonstrate that the striated domains consist of linear arrays of single TM peptides with a dominantly antiparallel organization in which the peptides interact with each other and with lipids. The peptide arrays are regularly spaced by +/-8.5 nm and are separated by somewhat perturbed gel-state lipids with hexagonally organized acyl chains, which have lost their tilt. This system provides an example of how domains of peptides and lipids can be formed in membranes as a result of a combination of specific peptide-peptide and peptide-lipid interactions.
Sparr
Emma
E
Department of Biochemistry of Membranes, Institute of Biomembranes, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands. emma.sparr@fkem1.lu.se
Ganchev
Dragomir N
DN
Snel
Margot M E
MM
Ridder
Anja N J A
AN
Kroon-Batenburg
Loes M J
LM
Chupin
Vladimir
V
Rijkers
Dirk T S
DT
Killian
J Antoinette
JA
de Kruijff
Ben
B
D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D000595:Amino Acid Sequence; D008051:Lipid Bilayers / Q000737:chemistry*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
D008051:Lipid Bilayers; D010455:Peptides; D015060:1,2-Dipalmitoylphosphatidylcholine