Department of Applied Chemistry and Life Science, Toyohashi University of Technology, Toyohashi 441-8580, Japan.
Int J Mol Sci. 2023 Apr 28;24(9):7999. doi: 10.3390/ijms24097999.
The gel-phase domains in a binary supported lipid bilayer (SLB) comprising dioleoylphosphatidylcholine (DOPC) and dipalmitoylphosphatidylcholine (DPPC) were localized on graphene oxide (GO) deposited on a SiO/Si substrate. We investigated the distribution of the gel-phase domains and the liquid crystalline (L) phase regions in DOPC+DPPC-SLB on thermally oxidized SiO/Si substrates with GO flakes to understand the mechanism of the domain localization on GO. Fluorescence microscopy and atomic force microscopy revealed that the gel-phase domains preferably distributed on GO flakes, whereas the fraction of the L-phase increased on the bare SiO surface which was not covered with the GO flakes. The gel-phase domain was condensed on GO more effectively at the lower cooling rate. We propose that nucleation of the gel-phase domain preferentially occurred on GO, whose surface has amphiphilic property, during the gel-phase domain formation. The domains of the liquid ordered (L) phase were also condensed on GO in a ternary bilayer containing cholesterol that was phase-separated to the L phase and the liquid disordered phase. Rigid domains segregates on GO during their formation process, leaving fluid components to the surrounding region of GO.
在包含二油酰基磷脂酰胆碱（DOPC）和二月桂酰基磷脂酰胆碱（DPPC）的二元支撑脂质双层（SLB）的凝胶相域定位于沉积在 SiO2/Si 基底上的氧化石墨烯（GO）上。我们研究了在具有 GO 薄片的热氧化 SiO2/Si 基底上的 DOPC+DPPC-SLB 中凝胶相域和液晶（L）相区域的分布，以了解在 GO 上定位域的机制。荧光显微镜和原子力显微镜显示，凝胶相域优先分布在 GO 薄片上，而在没有 GO 薄片覆盖的裸露 SiO 表面上，L 相的分数增加。在较低的冷却速率下，凝胶相域在 GO 上更有效地凝聚。我们提出，在凝胶相域形成过程中，具有两亲性的 GO 表面优先发生凝胶相域的成核。在含有胆固醇的三元双层中，也将分离到 L 相和无序相的有序液体（L）相域凝聚在 GO 上。刚性域在其形成过程中在 GO 上分离，将流体成分留在 GO 的周围区域。
