Poly(ethylene glycol)‐lipid conjugates inhibit phospholipase C‐induced lipid hydrolysis, liposome aggregation and fusion through independent mechanisms

FEBS Letters

Alonso, Alicia¹  Goñi, Félix M¹  Basáñez, Gorka¹ 

[1] Grupo Biomembranas (Unidad Asociada al CSIC), Departamento de Bioquı́mica, Universidad del Paı́s Vasco, Aptdo. 644, 48080 Bilbao, Spain

关键词: ANTS;    8-aminonaphthalene-1;    3;    6-trisulfonic acid;    DPX;    p-xylene-bis(pyridinium bromide);    LUV;    large unilamellar vesicle;    PEG;    poly(ethylene glycol);    PEG-PE;    distearoylphosphatidylethanolamine-poly(ethylene glycol 2000);    R18;    octadecylrhodamine B;    TMA-DPH;    1-(trimethylaminophenyl)-6-phenyl-1;    3;    5-hexatriene;   

DOI  :  10.1016/S0014-5793(97)00716-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Poly(ethylene glycol)-phosphatidylethanolamine (PEG-PE) conjugates have been introduced in liposomal compositions. The resulting large unilamellar vesicles were subjected to the action of phospholipase C. Enzyme-promoted vesicle aggregation and fusion were assayed in liposomes containing various proportions of PEG-PE. At PEG-PE concentrations above 1 mol% the rate of phospholipid hydrolysis decreases, perhaps because the PEG moiety hinders the enzyme from reaching the membrane surface. At concentrations above 0.1 mol% vesicle aggregation occurs at a slower rate, presumably because of the repulsive barrier properties or surface-grafted PEG. Lipid mixing decreases in parallel with vesicle aggregation. Finally, liposomal fusion rates measured as mixing of vesicle aqueous contents are decreased at or even below 0.1 mol%. The latter inhibition is due, apart from the reduced rates of lipid hydrolysis, vesicle aggregation and lipid mixing, to a PEG-PE-based stabilization of the lipid bilayer structure. Thus the observed low rates of contents mixing arise from three combined and independent inhibitory effects of PEG-PE.

【 授权许可】

Unknown