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Phospholipase cleavage of glycosylphosphatidylinositol reconstituted in liposomal membranes
Author(s) -
Villar Ana Victoria,
Goñi Félix M,
Alonso Alicia,
Jones David R,
León Yolanda,
Varela-Nieto Isabel
Publication year - 1998
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(98)00853-9
Subject(s) - phosphatidylcholine , liposome , vesicle , biochemistry , sphingomyelin , chemistry , phospholipid , phospholipase d , phosphatidylinositol , phospholipase c , lipid bilayer , phospholipase , phosphatidic acid , lecithin , bilayer , phosphatidylethanolamine , chromatography , membrane , enzyme , kinase
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.