Temperature- and composition-dependent conformational transitions of amphipathic peptide-phospholipid nanodiscs
Temperature- and composition-dependent conformational transitions of amphipathic peptide-phospholipid nanodiscs
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DOI：
10.1016/j.jcis.2020.12.090
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发表时间：
2021-01-09
影响因子：
9.9
通讯作者：
Nakano, Minoru
中科院分区：
文献类型：
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作者：
Anada, Chiharu;Ikeda, Keisuke;Nakano, Minoru
纳米盘是盘状颗粒，其中脂质双层被两亲分子如蛋白质、肽或合成聚合物包围。已知载脂蛋白A-I衍生肽18 A在磷脂存在下形成纳米盘，但这些纳米盘响应周围环境变化而形成和变形的详细机制尚不清楚。在这里，我们研究了温度和组成依赖的18 A-磷脂酰胆碱复合物的结构变化，使用荧光光谱，动态光散射，圆二色性，静态P-31 NMR和电子显微镜。我们发现，在快速各向同性旋转运动的纳米盘的尺寸增加以上的凝胶到液晶的相变温度的脂质双层，导致在扩大的纳米盘和层状相的形成。层状相被发现是沿着磁场取向。温度的进一步升高诱导脂质囊泡的形成。这些转换解释了使用过渡模型的基础上迁移的肽从边缘的纳米盘的液晶双层相。研究结果为理解盘状纳米结构在结构生物学和纳米医学应用中的设计原理提供了基础。(C)2020爱思唯尔公司All rights reserved.
Nanodiscs are discoidal particles in which a lipid bilayer is encircled by amphipathic molecules such as proteins, peptides, or synthetic polymers. The apolipoprotein-A-I-derived peptide 18A is known to form nanodiscs in the presence of phospholipids, but the detailed mechanism of the formation and deformation of these nanodiscs in response to changes in the surrounding environment is not well understood. Here, we investigated the temperature- and composition-dependent structural changes of 18A-phosphatidylcholine complexes using fluorescence spectroscopy, dynamic light scattering, circular dichroism, static P-31 NMR, and electron microscopy. We found that the nanodiscs in fast isotropic rotational motion increased in size above the gel-to-liquid-crystalline phase transition temperature of the lipid bilayers, resulting in the formation of enlarged nanodiscs and a lamellar phase. The lamellar phase was found to be oriented along the magnetic field. Further increase in temperature induced the formation of lipid vesicles. These transformations were explained using a transition model based on the migration of the peptide from the rim of the nanodiscs to the liquid-crystalline bilayer phase. The study outcomes provide a basis for understanding the design principles of discoidal nanostructures for structural biology and nanomedicine applications. (C) 2020 Elsevier Inc. All rights reserved.