Single-Unit Imaging of Membrane Protein-Embedded Nanodiscs from Two Oriented Sides by High-Speed Atomic Force Microscopy
Single-Unit Imaging of Membrane Protein-Embedded Nanodiscs from Two Oriented Sides by High-Speed Atomic Force Microscopy
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DOI：
10.1016/j.str.2018.09.005
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发表时间：
2019-01-02
期刊：
影响因子：
5.7
通讯作者：
Tsukazaki, Tomoya
中科院分区：
文献类型：
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作者：
Haruyama, Takamitsu;Sugano, Yasunori;Tsukazaki, Tomoya
膜蛋白在各种细胞功能中起重要作用。为了分析膜蛋白，使用膜支架蛋白的纳米盘技术允许单个膜蛋白单元在没有洗涤剂的情况下嵌入脂质双层盘中。高速原子力显微镜（HS-AFM）的最新进展使我们能够在纳米尺度上监测溶液中蛋白质的实时动态。在这项研究中，我们报告HS-AFM成像的膜蛋白重组成纳米盘使用两个膜蛋白复合物，SecYEG复合物和MgtE二聚体。观察到的图像显示膜蛋白嵌入的纳米盘的单个颗粒处于端向上取向，其中膜平行于支撑固体表面固定，并且处于侧上取向，其中膜平面垂直固定到固体表面，使得能够阐明膜蛋白中的结构域波动。该技术为HS-AFM对单个膜蛋白质的高分辨率成像提供了基本方法。
Membrane proteins play important roles in various cellular functions. To analyze membrane proteins, nanodisc technology using membrane scaffold proteins allows single membrane protein units to be embedded into the lipid bilayer disc without detergents. Recent advancements in high-speed atomic force microscopy (HS-AFM) have enabled us to monitor the real-time dynamics of proteins in solution at the nanometer scale. In this study, we report HS-AFM imaging of membrane proteins reconstituted into nanodiscs using two membrane protein complexes, SecYEG complex and MgtE dimer. The observed images showed single particles of membrane protein-embedded nanodiscs in an end-up orientation whereby the membrane was fixed parallel to the supporting solid surface and in a side-on orientation whereby the membrane plane was vertically fixed to the solid surface, enabling the elucidation of domain fluctuations in membrane proteins. This technique provides a basic method for the high-resolution imaging of single membrane proteins by HS-AFM.