A saposin-lipoprotein nanoparticle system for membrane proteins.
A saposin-lipoprotein nanoparticle system for membrane proteins.
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DOI：
10.1038/nmeth.3801
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发表时间：
2016-04
期刊：
影响因子：
48
通讯作者：
Nordlund P
中科院分区：
文献类型：
--
作者：
Frauenfeld J;Löving R;Armache JP;Sonnen AF;Guettou F;Moberg P;Zhu L;Jegerschöld C;Flayhan A;Briggs JA;Garoff H;Löw C;Cheng Y;Nordlund P
膜蛋白在生物学、药物发现和疫苗接种中具有突出的重要性。在涉及膜蛋白的研究和应用中，一个常见的限制因素是溶解和稳定膜蛋白的能力。尽管去污剂代表了溶解膜蛋白的主要手段，但它们通常与蛋白质不稳定性以及在结构和生物物理研究中的适用性差有关。在这里，我们提出了一种新的脂蛋白纳米颗粒系统，允许重建的膜蛋白进入脂质环境，是稳定的Saposin蛋白的支架。我们展示了该方法对两种纯化的膜蛋白复合物的适用性，以及从病毒膜直接溶解和纳米颗粒掺入病毒膜蛋白复合物。我们还表明，这种脂质纳米颗粒的方法有利于高分辨率的膜蛋白在脂质环境中的结构研究，通过单粒子电子冷冻显微镜（cryo-EM），并允许稳定的HIV包膜糖蛋白的功能状态。
Membrane proteins are of outstanding importance in biology, drug discovery and vaccination. A common limiting factor in research and applications involving membrane proteins is the ability to solubilize and stabilize membrane proteins. Although detergents represent the major means for solubilizing membrane proteins, they are often associated with protein instability and poor applicability in structural and biophysical studies. Here, we present a novel lipoprotein nanoparticle system that allows for the reconstitution of membrane proteins into a lipid environment that is stabilized by a scaffold of Saposin proteins. We showcase the applicability of the method on two purified membrane protein complexes as well as the direct solubilization and nanoparticle-incorporation of a viral membrane protein complex from the virus membrane. We also demonstrate that this lipid nanoparticle methodology facilitates high-resolution structural studies of membrane proteins in a lipid environment by single-particle electron cryo-microscopy (cryo-EM) and allows for the stabilization of the HIV-envelope glycoprotein in a functional state.