脂质组成改变的腹水肿瘤细胞中5'-核苷酸酶比活性及在两个质膜结构域间分布的变化

Altered 5'-nucleotidase specific activity and distribution between two plasma membrane domains of ascites tumor cells with modified lipid composition.

Haeffner E W, Seibicke S, Hoffmann C J

Institute of Cell and Tumor Biology, German Cancer Research Center, Heidelberg, F.R.G.

Int J Biochem. 1988;20(1):55-60. doi: 10.1016/0020-711x(88)90010-9.

Abstract

The cholesterol and phospholipid content of the surface membranes of ascites tumor cells cultivated in lipid-depleted medium was reduced to about 60(70)% of the control, but the relative composition of the individual phospholipids was not altered. 2. Differences in lipid composition were also observed between the two plasma membrane domains isolated from the cells cultured in normal and lipid-depleted medium respectively. 3. The fatty acid spectrum of the lipid-depleted membranes showed a greater fraction of saturated vs unsaturated acids. 4. The membrane lipid fluidity measured by fluorescence polarization was decreased in the modified surface membranes. 5. The 5'-nucleotidase specific activity was drastically reduced (46-66%) in the lipid-deleted membranes, and in addition its distribution between the two vesicle fractions was altered.

摘要

在脂质缺乏培养基中培养的腹水肿瘤细胞表面膜的胆固醇和磷脂含量降至对照的约60（70）%，但各磷脂的相对组成未改变。2. 分别从在正常培养基和脂质缺乏培养基中培养的细胞分离得到的两个质膜结构域之间也观察到脂质组成的差异。3. 脂质缺乏膜的脂肪酸谱显示饱和脂肪酸与不饱和脂肪酸的比例更高。4. 通过荧光偏振测量的膜脂流动性在修饰的表面膜中降低。5. 在脂质缺失的膜中，5'-核苷酸酶的比活性大幅降低（46 - 66%），此外其在两个囊泡组分之间的分布也发生了改变。