title: Effect of monolayer lipid charges on the structure and orientation of protein VAMP1 at the air-water interface.
abstract: SNARE proteins are implicated in membrane fusion during neurotransmission and peptide hormone secretion. Relatively little is known about the molecular interactions of their trans- and juxtamembrane domains with lipid membranes. Here, we report the structure and the assembling behavior of one of the SNARE proteins, VAMP1/synaptobrevin1 incorporated in a lipid monolayer at an air-water interface which mimics the membrane environment. Our results show that the protein is extremely sensitive to surface pressure as well as the lipid composition. Monolayers of proteins alone or in the presence of the neutral phospholipid DMPC underwent structural transition from alpha-helix to beta-sheet upon surface compression. In contrast, the anionic phospholipid DMPG inhibited this transition in a concentration-dependent manner. Moreover, the orientation of the proteins was highly sensitive to the charge density of the lipid layers. Thus, the structure of VAMP1 is clearly controlled by protein-lipid interactions.
authors.affiliation: Université de Bordeaux, UMR CBMN 5248, CNRS, Institut Européen de Chimie et Biologie, 2 Rue Robert Escarpit, F-33607 PESSAC, France.
authors.forename: Wissam
authors.initials: W
authors.lastname: Yassine
authors.forename: Alexandra
authors.initials: A
authors.lastname: Milochau
authors.forename: Sebastien
authors.initials: S
authors.lastname: Buchoux
authors.forename: Jochen
authors.initials: J
authors.lastname: Lang
authors.forename: Bernard
authors.initials: B
authors.lastname: Desbat
authors.forename: Reiko
authors.initials: R
authors.lastname: Oda
mesh_terms: D000388:Air; D000595:Amino Acid Sequence; D000818:Animals; D002462:Cell Membrane / Q000737:chemistry*; D004134:Dimyristoylphosphatidylcholine / Q000737:chemistry; D007202:Indicators and Reagents / Q000737:chemistry; D008055:Lipids / Q000737:chemistry*; D008853:Microscopy / Q000379:methods; D008969:Molecular Sequence Data; D010715:Phosphatidylglycerols / Q000737:chemistry; D017433:Protein Structure, Secondary; D051381:Rats; D013057:Spectrum Analysis / Q000379:methods; D050987:Vesicle-Associated Membrane Protein 1 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D014867:Water / Q000737:chemistry
chemical_list: D007202:Indicators and Reagents; D008055:Lipids; D010715:Phosphatidylglycerols; D050987:Vesicle-Associated Membrane Protein 1; D014867:Water; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine