Intramolecular excimer kinetics of fluorescent dipyrenyl lipids: 2. DOPE/DOPC membranes.
Intramolecular excimer kinetics of fluorescent dipyrenyl lipids: 2. DOPE/DOPC membranes.
复制标题
荧光二芘基脂质的分子内准分子动力学：2. DOPE/DOPC 膜。
DOI：
10.1016/s0006-3495(94)80553-3
复制
发表时间：
1994
影响因子：
3.4
通讯作者：
Sugar,IP
中科院分区：
文献类型：
--
作者：
Cheng,KH;Ruymgaart,L;Liu,LI;Somerharju,P;Sugar,IP
用频域荧光强度衰减技术研究了不同链长（n）的二芘基脂质（DipynPE）在完全水合的二油酰磷脂酰乙醇胺（DOPE）和二油酰磷脂酰胆碱（DOPC）二元混合物中的分子内动力学。使用3态模型（见配套文件），聚集的程度和旋转速率的两个共价连接的芘部分在DipynPE估计从频域数据。在1 ℃下，Dipy4PE和Dipy10PE的旋转速率和聚集对脂质双层的DOPE%不敏感。在27 ℃下，旋转速率降低，而随着双层的DOPE%从0增加到80，Dipy10PE的聚集稳定增加。然而，当DOPE%达到100时，检测到Dipy10PE的旋转速率的突然增加和聚集的减少，此时膜处于倒六方（HII）相。Dipy4PE未发现类似变化。这些结果表明，具有大的固有曲率的PE的存在下，在双层的中心附近的区域处的侧向应力增加，并且该应力可以被释放，因为膜进入高度弯曲的HII相。
The intramolecular dynamics of the excimer-forming dipyrenyl lipids (DipynPE) of different chain lengths (n) in fully hydrated dioleoylphosphatidylethanolamine (DOPE) and dioleoylphosphatidylcholine (DOPC) binary mixtures was investigated by the use of frequency-domain fluorescence intensity dcay technique. Using a 3-state model (see companion paper), the extent of aggregation and rotational rate of the two covalently attached pyrene moieties in DipynPE were estimated from the frequency-domain data. At 1 degrees C, the rotational rate and aggregation for Dipy4PE and Dipy10PE were insensitive to DOPE% of the lipid bilayer. At 27 degrees C, the rotational rate decreased, whereas the aggregation increased steadily for Dipy10PE as the DOPE% of the bilayer increased from 0 to 80. However, an abrupt increase in the rotational rate and a decrease in the aggregation for Dipy10PE were detected as the DOPE% reached 100, at which point the membranes are in the inverted hexagonal (HII) phase. No similar changes were found for Dipy4PE. These results indicate that the presence of PE with large intrinsic-curvature increases the lateral stress at the region near the center of the bilayer, and that this stress can be relieved as the membranes enter the highly curved HII phase.