Bayburt Timothy H, Grinkova Yelena V, Sligar Stephen G
Department of Biochemistry, University of Illinois, 116 Morrill Hall, 505 S. Goodwin, Urbana, IL 61801, USA.
Arch Biochem Biophys. 2006 Jun 15;450(2):215-22. doi: 10.1016/j.abb.2006.03.013. Epub 2006 Mar 29.
Nanodiscs, phospholipid bilayer assemblies of controlled size, were used to self-assemble bacteriorhodopsin (bR) into single trimers. Self-assembly at optimal bR to Nanodisc and phospholipid stoichiometry yielded particles containing three bR molecules. Analysis of solution small angle X-ray scattering indicated that bacteriorhodopsin is embedded in a discoidal phospholipid bilayer structure. Formation of trimers, as evidenced by visible circular dichroism of the retinal absorbance bands, is facilitated in Nanodiscs at a specific size threshold, suggesting that a critical bilayer area or amount of lipid is necessary to maintain a native oligomeric state. The lipid to bR ratio in the assembly process was also found to be an important factor in determining oligomerization state. These nanoscale bilayers offer the opportunity to understand and control the assembly of oligomeric integral membrane proteins critical to macromolecular recognition and cellular signaling.
纳米盘是大小可控的磷脂双分子层组装体，用于将细菌视紫红质（bR）自组装成单个三聚体。在bR与纳米盘及磷脂的最佳化学计量比下进行自组装，得到了含有三个bR分子的颗粒。溶液小角X射线散射分析表明，细菌视紫红质嵌入盘状磷脂双分子层结构中。视网膜吸收带的可见圆二色性证明，在特定尺寸阈值下，纳米盘中有利于三聚体的形成，这表明维持天然寡聚状态需要临界双分子层面积或一定量的脂质。组装过程中的脂质与bR比例也是决定寡聚化状态的一个重要因素。这些纳米级双分子层为理解和控制对大分子识别和细胞信号传导至关重要的寡聚整合膜蛋白的组装提供了机会。
