Phospholipase cleavage of glycosylphosphatidylinositol reconstituted in liposomal membranes

FEBS Letters

Alonso, Alicia²  León, Yolanda¹  Goñi, Félix M²  Varela-Nieto, Isabel¹  Villar, Ana Victoria²  Jones, David R¹ 

[1] Department of Cell Signalling, Instituto de Investigaciones Biomédicas, C.S.I.C., Arturo Duperier 4, 28029 Madrid, Spain;Grupo Biomembranas (Unidad Asociada al C.S.I.C.), Departamento de Bioquı́mica, Universidad del Paı́s Vasco, Aptdo. 644, 48080 Bilbao, Spain

关键词: Glycosylphosphatidylinositol;    Phospholipase;    Liposomal membrane;    GPI;    glycosylphosphatidylinositol;    IPG;    inositol phosphoglycans;    PI-PLC;    phosphatidylinositol-specific phospholipase D;    GPI-PLD;    glycosylphosphatidylinositol-specific phospholipase D;    GPI-PLC;    glycosylphosphatidylinositol-specific phospholipase C;    PC-PLC;    phosphatidylcholine-preferring phospholipase C;    LUV;    large unilamellar vesicles;    PC;    phosphatidylcholine;    PE;    phosphatidylethanolamine;    PA;    phosphatidic acid;    PI;    phosphatidylinositol;    SM;    sphingomyelin;    Ch;    cholesterol;    ANTS/DPX;    8-aminonaphthalene-1;    3;    6-trisulphonic acid/p-xylylene bis (pyridinium bromide);   

DOI  :  10.1016/S0014-5793(98)00853-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Glycosylphosphatidylinositol (GPI) purified from rat liver lipids was incorporated into lipid bilayers of defined compositions, in the form of large unilamellar vesicles. The GPI concentration in the bilayers was kept constant at 25 mole%, whereas the remaining lipids being phosphatidylcholine, phosphastidylethanolamine, sphingomyelin and/or cholesterol were varied. The resulting liposomes consisted of spherical vesicles, approximately 100 nm in diameter, that could keep their aqueous contents separated from the extravesicular medium. When these liposomes were treated with either Bacillus cereus phosphatidylinositol-phospholipase C, Trypanosoma brucei GPI-phospholipase C, or bovine serum GPI-phospholipase D, GPI was hydrolyzed at different rates, depending on the enzyme and the bilayer lipid composition. These observations open the way to biophysical and biochemical studies of enzymic GPI cleavage under defined conditions. Extensive GPI hydrolysis was observed in certain cases that could allow the use of these systems for the preparation of inositol phosphoglycans, proposed second messengers of a wide variety of hormones, cytokines and growth factors.

【 授权许可】

Unknown