Directed self-assembly of monodisperse phospholipid bilayer nanodiscs with controlled size
Directed self-assembly of monodisperse phospholipid bilayer nanodiscs with controlled size
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DOI：
10.1021/ja0393574
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发表时间：
2004-03-24
影响因子：
15
通讯作者：
Sligar, SG
中科院分区：
文献类型：
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作者：
Denisov, IG;Grinkova, YV;Sligar, SG
使用最近描述的自组装过程（Bayburt，T. H.的; Grinkova，Y.五、Sligar，S. G. Nano Letters 2002，2，853 - 856），我们制备了具有受控尺寸和组成的可溶性单分散盘状脂质/蛋白质颗粒，称为纳米盘，其中二棕榈酰磷脂酰胆碱（DPPC）双层的片段被螺旋蛋白质带包围。我们通过改变这条带的两亲螺旋部分的长度来定制这些颗粒的大小，称为膜支架蛋白（MSP）。在这里，我们描述了扩展和截短的MSP的设计，这些蛋白质的自组装的优化，以及所得到的纳米盘的结构和组成。我们发现，纳米盘的脂质部分周围的蛋白质螺旋的长度决定了粒径，通过HPLC和小角X射线散射（SAXS）测量。使用不同的支架蛋白，我们获得了平均尺寸为9.5至12.8 nm的纳米盘，具有非常窄的尺寸分布（+/-3%）。支架蛋白的N-末端的功能化不会干扰它们形成均匀盘状结构的能力。溶液散射的详细分析证实了在不同尺寸的纳米盘中存在5.5nm厚度的脂质双层。本研究的结果提供了一个重要的自组装磷脂双分子层的结构表征，并建立了一个框架的设计控制尺寸的可溶性两亲性纳米粒子。
Using a recently described self-assembly process (Bayburt, T. H.; Grinkova, Y. V.; Sligar, S. G. Nano Letters 2002, 2, 853-856), we prepared soluble monodisperse discoidal lipid/protein particles with controlled size and composition, termed Nanodiscs, in which the fragment of dipalmitoylphosphatidylcholine (DPPC) bilayer is surrounded by a helical protein belt. We have customized the size of these particles by changing the length of the amphipathic helical part of this belt, termed membrane scaffold protein (MSP). Herein we describe the design of extended and truncated MSPs, the optimization of self-assembly for each of these proteins, and the structure and composition of the resulting Nanodiscs. We show that the length of the protein helix surrounding the lipid part of a Nanodisc determines the particle diameter, as measured by HPLC and small-angle X-ray scattering (SAXS). Using different scaffold proteins, we obtained Nanodiscs with the average size from 9.5 to 12.8 nm with a very narrow size distribution (+/-3%). Functionalization of the N-terminus of the scaffold protein does not perturb their ability to form homogeneous discoidal structures. Detailed analysis of the solution scattering confirms the presence of a lipid bilayer of 5.5 nm thickness in Nanodiscs of different sizes. The results of this study provide an important structural characterization of self-assembled phospholipid bilayers and establish a framework for the design of soluble amphiphilic nanoparticles of controlled size.