Effect of monolayer lipid charges on the structure and orientation of protein VAMP1 at the air-water interface.
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.
Yassine
Wissam
W
Université de Bordeaux, UMR CBMN 5248, CNRS, Institut Européen de Chimie et Biologie, 2 Rue Robert Escarpit, F-33607 PESSAC, France.
Milochau
Alexandra
A
Buchoux
Sebastien
S
Lang
Jochen
J
Desbat
Bernard
B
Oda
Reiko
R
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
D007202:Indicators and Reagents; D008055:Lipids; D010715:Phosphatidylglycerols; D050987:Vesicle-Associated Membrane Protein 1; D014867:Water; C002773:dimyristoylphosphatidylglycerol; D004134:Dimyristoylphosphatidylcholine