Substrate-Induced Structure and Molecular Dynamics in a Lipid Bilayer Membrane
Substrate-Induced Structure and Molecular Dynamics in a Lipid Bilayer Membrane
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DOI：
10.1021/acs.langmuir.7b03212
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发表时间：
2017-12-26
期刊：
影响因子：
3.9
通讯作者：
Tero, Ryugo
中科院分区：
文献类型：
--
作者：
Motegi, Toshinori;Yamazaki, Kenji;Tero, Ryugo
通过原子力显微镜（AFM）和单粒子跟踪（SPT）测量直接研究了负载型脂质双分子层（SLB）中依赖固体基质的分子结构和动力学。发现SLB中垂直或水平异质性的出现强烈依赖于底层基质。SLB已被广泛应用于与蛋白质和其他生物材料结合的生物界面。二氧化硅和云母都是SLB的常用衬底。利用单分子动力学方法，发现上膜和下膜的流动性取决于衬底，分别在SiO2/Si和云母衬底上发生耦合和解耦。由于SLB与Al2O3（0001）衬底之间存在强烈的范德华相互作用，导致SLB在原子阶上局部失稳结构引起的各向异性扩散出现在Al2O3（0001）衬底上。我们发现云母和蓝宝石表面的明确定义导致了质膜的不对称性和各向异性，这对设计新的模拟质膜系统是有用的。明确定义的slb支撑基质的应用应该具有与细胞膜支架相似的作用，可以调节膜的动态结构。
The solid-substrate-dependent structure and dynamics of molecules in a supported lipid bilayer (SLB) were directly investigated via atomic force microscopy (AFM) and single particle tracking (SPT) measurements. The appearance of either vertical or horizontal heterogeneities in the SLB was found to be strongly dependent on the underlying substrates. SLB has been widely used as a biointerface with incorporated proteins and other biological materials. Both silica and mica are popular substrates for SLB. Using single-molecule dynamics, the fluidity of the upper and lower membrane leaflets was found to depend on the substrate, undergoing coupling and decoupling on the SiO2/Si and mica substrates, respectively. The anisotropic diffusion caused by the locally destabilized structure of the SLB at atomic steps appeared on the Al2O3(0001) substrate because of the strong van der Waals interaction between the SLB and the substrate. Our finding that the well-defined surfaces of mica and sapphire result in asymmetry and anisotropy in the plasma membrane is useful for the design of new plasma-membrane-mimetic systems. The application of well-defined supporting substrates for SLBs should have similar effects as cell membrane scaffolds, which regulate the dynamic structure of the membrane.