title: The membrane-induced structure of melittin is correlated with the fluidity of the lipids.
abstract: The effect of the bee toxin melittin on DMPC dynamics in fast-tumbling bicelles has been investigated. The (13)C R(1) and (13)C-(1)H NOE relaxation parameters for DMPC were used to monitor the effect of melittin and cholesterol on lipid dynamics. It was found that melittin has the largest effect on the DMPC mobility in DMPC/DHPC bicelles, while less effect was observed in cholesterol-doped bicelles, or in bicelles made with CHAPS, indicating that the rigidity of the membrane affects the melittin-membrane interaction. CD spectra were analysed in terms of cooperativity of the alpha-helix to random coil transition in melittin, and these results also indicated similar differences between the bicelles. The study shows that bicelles can be used to investigate lipid dynamics by spin relaxation, and in particular of peptide-induced changes in membrane fluidity.
authors.affiliation: Department of Biochemistry and Biophysics, The Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden.
authors.forename: August
authors.initials: A
authors.lastname: Andersson
authors.forename: Henrik
authors.initials: H
authors.lastname: Biverståhl
authors.forename: Jon
authors.initials: J
authors.lastname: Nordin
authors.forename: Jens
authors.initials: J
authors.lastname: Danielsson
authors.forename: Emma
authors.initials: E
authors.lastname: Lindahl
authors.forename: Lena
authors.initials: L
authors.lastname: Mäler
mesh_terms: D002784:Cholesterol / Q000737:chemistry; D002793:Cholic Acids / Q000737:chemistry; D002942:Circular Dichroism; D003902:Detergents / Q000737:chemistry; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D008051:Lipid Bilayers / Q000737:chemistry* / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008555:Melitten / Q000737:chemistry* / Q000378:metabolism; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000737:chemistry* / Q000378:metabolism; D008968:Molecular Conformation; D010742:Phospholipid Ethers / Q000737:chemistry; D011485:Protein Binding; D017433:Protein Structure, Secondary; D013050:Spectrometry, Fluorescence; D013113:Spin Labels; D013696:Temperature
chemical_list: C052298:1,2-dihexadecyl-sn-glycero-3-phosphocholine; D002793:Cholic Acids; D003902:Detergents; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010742:Phospholipid Ethers; D013113:Spin Labels; D008555:Melitten; D002784:Cholesterol; C028213:3-((3-cholamidopropyl)dimethylammonium)-1-propanesulfonate; D004134:Dimyristoylphosphatidylcholine