胆酸对人工细胞膜流动性的影响

Influences on Fluidity of Artificial Cell Membrane by Cholic Acid

摘要: 以天然磷脂1,2-二-十四烷基磷脂酰胆碱(DMPC)和合成肽脂Ala制备人工细胞膜，向不同样品中分别加入10%、20%、30%的胆酸，以1,6-二苯基-1,3,5-己三烯(DPH)作为荧光试剂，利用荧光偏光法检测不同浓度胆酸对人工细胞膜的流动性的影响。结果表明，在实验设置的温度范围内，不同浓度的胆酸对DMPC囊泡的流动性影响不大。Ala囊泡在凝胶态温度下，随着胆酸浓度的增加，偏光值P值逐渐减小，流动性增大；而在液晶态温度下，不同浓度胆酸对Ala囊泡的流动性影响不大。本实验为阐明生物体内胆酸和细胞膜的相互作用机理提供了参考依据。

Abstract: The natural phospholipid DMPC and Ala, a kind of synthetic peptide lipid, were used to prepare artificial cell membrane vesicles. 10%, 20% and 30% cholic acid were added into the samples, re-spectively. DPH was taken as the fluorescence reagent and the influences on the fluidity of two kinds of vesicle samples were examined by fluorescence polarization technology. The results showed that in the setting temperature range, cholic acid of different concentrations had little effect on the fluidity of DMPC vesicles. For Ala vesicles, in the temperature range of gel phase, polarization value decreased while the fluidity increased with the elevation of cholic acid concentrations. However, in the temperature range of liquid phase, cholic acid of different concentrations showed little effect. This research provides the theory basis on interaction mechanism of cholic acid and cell membrane in the natural organism.