Lysophosphatidylcholine mediates the mode of insertion of the NH2‐terminal SIV fusion peptide into the lipid bilayer

FEBS Letters

Dubois, M.-C.²  Ruysschaert, J.-M.²  Saermark, T.³  Martin, I.²  Epand, R.M.¹ 

[1] Department of Biochemistry, McMaster University, 1200 Main Street West, Hamilton, Ont., L8N 3Z5, Canada;Laboratoire de Chimie-Physique des Macromolécules aux Interfaces, Université Libre de Bruxelles, Campus Plaine CP 206/2, B-1050 Brussels, Belgium;C/O Neurosearch, Smedeland 26, 26000 Glostrup, Denmark

关键词: SIV fusion peptide;    lysoPC;    Lipid mixing;    FTIR spectroscopy;   

DOI  :  10.1016/0014-5793(93)80680-S

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We report here on the interaction of a synthetic 12 residue peptide corresponding to the N-terminal sequence of gp32 from SIV with phospholipid bilayers. This peptide has been shown to induce lipid mixing of PC/PE/SM/Chol LUV (large unilamellar vesicles) at pH 7.4 and 37°C [(1992) in: Advances in Membrane Fluidity, vol. 6, pp. 365-376, Wiley-Liss]. In the present study, this fusion process was inhibited by the addition of lysophosphatidylcholine (lysoPC) to the lipid bilayer of PC/PE/SM/Chol LUV. Fourier transform infrared spectroscopy (FTIR) reveals that the orientation of the SIV fusion peptide with respect to the lipid acyl chains depends on the presence of lysoPC in the lipid bilayer but that the peptide secondary structure and the amount of lipid-associated peptides do not depend on the lipid composition. The peptide is obliquely inserted into the lipid bilayer of vesicles without lysoPC, whereas it is oriented parallel to the lipid-water interface in the vesicles containing lysoPC. The data provide evidence that the orientation of the SIV fusion peptide depends on the lipid composition, and that this mediates its fusogenic activity.

【 授权许可】

Unknown