University of Ljubljana, Slovenia.
Biophys Chem. 2011 Oct;158(2-3):150-6. doi: 10.1016/j.bpc.2011.06.014. Epub 2011 Jun 30.
The physicochemical properties of binary lipid mixtures of diether C(25,25) lipids and dipalmitoyl-L-α-phosphatidylcholine (DPPC) were studied using photon correlation, fluorescence and electron paramagnetic resonance spectroscopy, and transmission electron microscopy. These two types of lipids can be mixed at all molar ratios to form unilamellar and multilamellar liposomes. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatrien in mixed liposomes indicates that the abrupt changes in order parameter in the hydrophobic part of bilayer membranes made of DPPC lipids disappears with increasing mol%C(25,25) lipids. Electron paramagnetic resonance spectroscopy shows that at temperatures below 50 °C, the interfacial regions of membrane bilayer of mixed liposomes is more fluid than for pure DPPC liposomes, while at higher temperatures, the impact of the long isoprenoid chains on the membrane stability becomes more pronounced. Photon correlation spectroscopy and transmission electron microscopy show that mixed liposomes do not fuse or aggregate, even after 41 days at 4 °C.
采用光子相关、荧光和电子顺磁共振波谱以及透射电子显微镜研究了二醚 C(25,25)脂质和二棕榈酰-L-α-磷脂酰胆碱 (DPPC) 的二元脂质混合物的物理化学性质。这两种类型的脂质可以以任意摩尔比混合形成单层和多层脂质体。混合脂质体中 1,6-二苯基-1,3,5-己三烯的荧光各向异性表明，由 DPPC 脂质组成的双层膜疏水区的有序参数的突然变化随着 C(25,25)脂质摩尔%的增加而消失。电子顺磁共振波谱表明，在低于 50°C 的温度下，混合脂质体的膜双层的界面区域比纯 DPPC 脂质体更具流动性，而在较高温度下，长异戊二烯链对膜稳定性的影响变得更加明显。光子相关光谱和透射电子显微镜表明，混合脂质体即使在 4°C 下放置 41 天也不会融合或聚集。
