Thermodynamic and phase characterization of phosphatidylethanolamine and ganglioside GD1a mixtures.
Thermodynamic and phase characterization of phosphatidylethanolamine and ganglioside GD1a mixtures.
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磷脂酰乙醇胺和神经节苷脂 GD1a 混合物的热力学和相表征。
DOI：
10.1016/0005-2736(87)90280-x
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
Huang,L
中科院分区：
文献类型：
--
作者：
Tsao,YS;Freire,E;Huang,L
通过采用二苯基己三烯稳态荧光各向异性、芘癸酸准分子形成和高灵敏度扫描量热法，我们证明了含有磷脂酰乙醇胺（PE）和不同摩尔分数的神经节苷脂GD1a的脂质体在15°C和25°C之间具有凝胶-液晶相变。量热测量表明这些相变很宽并且集中在17°C和21°C之间。转变的焓变与神经节苷脂浓度线性相关，最高可达 10.0 mol%，并稳定在 11.4–16.2 mol% 之间。高焓变（37 kcal/mol GD1a 添加到 PE 双层中）表明脂质体膜中存在 PE-GD1a 复合结构。据推测，在高于凝胶-液晶相变的温度下，PE-GD1 膜中存在包含六个 PE 和一个神经节苷脂分子的半流体域。仙台病毒诱导的 PE-GD1 脂质体渗漏已通过使用包埋的自猝灭荧光染料钙黄绿素进行了研究。渗漏率取决于神经节苷脂GD1a的摩尔分数，在6.3 mol%时达到最大。泄漏率的阿伦尼乌斯图显示在 20-25°C 温度范围内出现中断，这对应于目标脂质体的凝胶-液晶相变。这些数据表明，仙台病毒引起的渗漏率可以通过在恒温下改变 PE 与 GD1 的比例来调节流动性。
By employing diphenylhexatriene steady-state fluorescence anisotropy, pyrenedecanoic acid excimer formation, and high sensitivity scanning calorimetry we have demonstrated that the liposomes containing phosphatidylethanolamine (PE) and various mole fractions of ganglioside GD1ahad a gel-liquid crystalline phase transition between 15 and 25° C. Calorimetric measurements indicated that these phase transitions were broad and centered between 17 and 21° C. The enthalpy change of the transition was linearly dependent on the ganglioside concentration up to 10.0 mol% and plateaued between 11.4–16.2 mol%. The high enthalpy change (37 kcal/mol of GD1aadded into the PE bilayer) indicates the existence of PE-GD1acomplex structure in the liposomal membrane. It is proposed that semi-fluid domains containing six PE and one ganglioside molecule are present in the PE-GD1amembranes at temperatures above gel-liquid crystalline phase transition. The Sendai virus induced leakage of PE-GD1aliposomes has been investigated by using an entrapped, self-quenching fluorescent dye, calcein. The leakage rate was dependent on the mole fraction of ganglioside GD1aand was maximal at 6.3 mol%. Arrhenius plots of the leakage rates showed breaks in the 20–25° C temperature range, which correspond to the gel-liquid crystalline phase transition of the target liposomes. These data suggest that the rate of Sendai virus-induced leakage can be regulated via fluidity modulation by changing the PE to GD1aratio at constant temperatures.