Stiasny Karin, Bressanelli Stéphane, Lepault Jean, Rey Felix A, Heinz Franz X
Institute of Virology, University of Vienna, A1095 Vienna, Austria.
J Virol. 2004 Mar;78(6):3178-83. doi: 10.1128/jvi.78.6.3178-3183.2004.
The interaction of a dimeric membrane anchor-free form of the envelope protein E (sE dimer) from tick-borne encephalitis virus with liposomes at acidic pH levels leads to its conversion into membrane-inserted sE trimers. Electron microscopy shows that these trimers have their long dimensions along the threefold molecular axis, which is oriented perpendicularly to the plane of the membrane, where the protein inserts via the internal fusion peptide. Liposomes containing sE at their surface display paracrystalline arrays of protein in a closely packing arrangement in which each trimer is surrounded by six others, suggesting cooperativity in the insertion process. sE trimers, solubilized with nonionic detergents, yielded three-dimensional crystals suitable for X-ray diffraction analysis.
蜱传脑炎病毒包膜蛋白E的无膜锚定二聚体形式（sE二聚体）在酸性pH水平下与脂质体相互作用，会使其转变为插入膜中的sE三聚体。电子显微镜显示，这些三聚体的长轴沿着三重分子轴方向，该轴垂直于膜平面，蛋白质通过内部融合肽插入膜中。表面含有sE的脂质体呈现出蛋白质的准晶体阵列，排列紧密，每个三聚体被其他六个三聚体包围，这表明插入过程中存在协同作用。用非离子去污剂溶解的sE三聚体产生了适合X射线衍射分析的三维晶体。
