L'Heureux G P, Fragata M
Centre de recherche en photobiophysique, Université du Québec à Trois-Rivières, Canada.
Biophys Chem. 1988 Jul 15;30(3):293-301. doi: 10.1016/0301-4622(88)85024-5.
The excimer/monomer ratio of emission intensities (IE/IM) and the enhancement of the 0-0 vibronic transition in the fluorescence spectra of pyrene (PY) and 16-(1-pyrenyl)hexadecanoic acid (C16PY) were used to investigate the localization of PY in the bilayers of small unilamellar vesicles constituted of phosphatidylcholine (SUV-PC). First, from comparison of the fluorescence characteristics of PY in water with those of PY incorporated into the SUV-PC membranes, we concluded that the probe is incorporated preferentially in the lipid phase of the vesicles and not in the bulk aqueous phase. In addition, we found that, contrary to what happens with the pyrenyl moiety of C16PY, the location of PY varies with its relative concentration in the membrane space. The critical concentration was observed to be around 1.0 mol% of incorporated PY. At concentrations below this value, PY is located in the hydrocarbon core of the lipid bilayers. Above 1.0 mol%, the PY molecules reside preferentially in the neighbourhood of the glyceryl moiety region of the PC vesicles.
利用芘（PY）和16 - （1 - 芘基）十六烷酸（C16PY）荧光光谱中发射强度的准分子/单体比率（IE/IM）以及0 - 0振动跃迁的增强，来研究PY在由磷脂酰胆碱构成的小单层囊泡（SUV - PC）双层膜中的定位。首先，通过比较水中PY与掺入SUV - PC膜中的PY的荧光特性，我们得出该探针优先掺入囊泡的脂质相而非本体水相。此外，我们发现，与C16PY的芘基部分不同，PY的位置随其在膜空间中的相对浓度而变化。观察到临界浓度约为掺入PY的1.0摩尔％。在该值以下的浓度下，PY位于脂质双层的烃核中。高于1.0摩尔％时，PY分子优先存在于PC囊泡甘油部分区域附近。
