Zolese G, Gratton E, Curatola G
Institute of Biochemistry, University of Ancona, Italy.
Chem Phys Lipids. 1990 Jul;55(1):29-39. doi: 10.1016/0009-3084(90)90146-i.
The fluorescence decay of 1-(4-trimethylammonium-phenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) was used to study micro-heterogeneity of 1,2-dimyristoyl-3-sn-phosphatidylcholine (DMPC) liposomes and to characterize the effect of phosphatidic acid on the correlation between fluorescence microheterogeneity and membrane permeability. The fluorescence decay, measured using multifrequency phase fluorometry, has been analyzed either by using a model of discrete exponential components or a model of continuous distribution of lifetime values. Both analyses have shown that TMA-DPH decay is characterized by two components: a long one of about 9 ns and a short one of about 5 ns. In the gel phase, at variance with previous DPH studies, the short component was associated with a large fractional intensity. The distributional analysis showed changes of lifetime values and width in correspondence to the calorimetric transitions. The presence of egg phosphatidic acid increased both long lifetime values and distributional width. The use of TMA-DPH as a probe to evaluate membrane heterogeneity using the distributional width is discussed. The effect of phosphatidic acid on the membrane surface and in the hydrophobic core has been related to its structural properties and to its role in water penetration.
利用1-(4-三甲基铵苯基)-6-苯基-1,3,5-己三烯（TMA-DPH）的荧光衰减来研究1,2-二肉豆蔻酰基-3- sn -磷脂酰胆碱（DMPC）脂质体的微异质性，并表征磷脂酸对荧光微异质性与膜通透性之间相关性的影响。使用多频相荧光法测量的荧光衰减，已通过使用离散指数成分模型或寿命值连续分布模型进行分析。两种分析均表明，TMA-DPH衰减具有两个成分：一个约9 ns的长成分和一个约5 ns的短成分。在凝胶相中，与先前的DPH研究不同，短成分与较大的分数强度相关。分布分析表明，寿命值和宽度的变化与量热转变相对应。卵磷脂酸的存在增加了长寿命值和分布宽度。讨论了使用TMA-DPH作为探针通过分布宽度评估膜异质性的方法。磷脂酸在膜表面和疏水核心中的作用与其结构特性及其在水渗透中的作用有关。
