Weng Chi-Jung, Wu Ju-Ping, Kuo Ming-Yen, Hsueh Ya-Wei
a Department of Physics , National Central University , Jhong-li , Taiwan.
Mol Membr Biol. 2016 Mar;33(1-2):23-28. doi: 10.1080/09687688.2016.1185175. Epub 2016 Jul 25.
To investigate the effect of fluorescent probe on the properties of membranes, we studied model membranes composed of 1,2- dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) and 1-palmitoyl 2-oleoyl-sn-glycero-3-phosphocholine (POPC) in the presence and absence of fluorescent probe. The morphology of giant unilamellar vesicles (GUVs) has been observed as a function of temperature and composition by fluorescence microscopy using NBD-DOPE or C-NBD-PC as the probe. The phase behavior of model membranes containing no fluorescent probe was investigated by H-NMR spectroscopy. We found that the bright phase observed on GUVs was the fluid phase enriched in POPC and the dark phase was the gel phase enriched in DPPC. NBD-DOPE and C-NBD-PC preferentially participated in the fluid-phase domains when GUVs were in the gel + fluid phase coexistence. Inclusion of both fluorescent probes (1 mol%) lowered the transition temperature of POPC/DPPC membranes. In addition, C-NBD-PC exhibited a stronger effect than NBD-DOPE, which was considered to be associated with the structures of fluorescent molecules.
为了研究荧光探针对膜性质的影响，我们研究了在有和没有荧光探针存在的情况下，由1,2 - 二棕榈酰 - sn - 甘油 - 3 - 磷酸胆碱（DPPC）和1 - 棕榈酰 - 2 - 油酰 - sn - 甘油 - 3 - 磷酸胆碱（POPC）组成的模型膜。使用NBD - DOPE或C - NBD - PC作为探针，通过荧光显微镜观察了巨型单层囊泡（GUVs）的形态随温度和组成的变化。通过H - NMR光谱研究了不含荧光探针的模型膜的相行为。我们发现，在GUVs上观察到的亮相是富含POPC的流体相，暗相是富含DPPC的凝胶相。当GUVs处于凝胶 + 流体相共存时，NBD - DOPE和C - NBD - PC优先参与流体相区域。同时加入两种荧光探针（1 mol%）会降低POPC/DPPC膜的转变温度。此外，C - NBD - PC表现出比NBD - DOPE更强的效果，这被认为与荧光分子的结构有关。
