Rutten Lucy, Gilman Morgan S A, Blokland Sven, Juraszek Jarek, McLellan Jason S, Langedijk Johannes P M
Janssen Vaccines & Prevention, Archimedesweg 4-6, Leiden 2333 CN, the Netherlands.
Department of Molecular Biosciences, The University of Texas at Austin, Austin, TX 78712, USA.
Cell Rep. 2020 Mar 31;30(13):4540-4550.e3. doi: 10.1016/j.celrep.2020.03.025.
Ebola virus causes severe hemorrhagic fever, often leading to death in humans. The trimeric fusion glycoprotein (GP) is the sole target for neutralizing antibodies and is the major focus of vaccine development. Soluble GP ectodomains are unstable and mostly monomeric when not fused to a heterologous trimerization domain. Here, we report structure-based designs of Ebola and Marburg GP trimers based on a stabilizing mutation in the hinge loop in refolding region 1 and substitution of a partially buried charge at the interface of the GP1 and GP2 subunits. The combined substitutions (T577P and K588F) substantially increased trimer expression for Ebola GP proteins. We determined the crystal structure of stabilized GP from the Makona Zaire ebolavirus strain without a trimerization domain or complexed ligand. The structure reveals that the stabilized GP adopts the same trimeric prefusion conformation, provides insight into triggering of GP conformational changes, and should inform future filovirus vaccine development.
埃博拉病毒可引发严重的出血热，常常导致人类死亡。三聚体融合糖蛋白（GP）是中和抗体的唯一靶点，也是疫苗研发的主要焦点。可溶性GP胞外域不稳定，在未与异源三聚化结构域融合时大多呈单体状态。在此，我们报告了基于埃博拉病毒和马尔堡病毒GP三聚体的结构设计，该设计基于重折叠区域1铰链环中的一个稳定突变以及GP1和GP2亚基界面处一个部分埋藏电荷的替换。组合替换（T577P和K588F）显著提高了埃博拉病毒GP蛋白的三聚体表达。我们确定了来自马科纳扎伊尔埃博拉病毒株的稳定化GP的晶体结构，该结构无三聚化结构域或复合配体。该结构表明，稳定化GP采用相同的三聚体预融合构象，为GP构象变化的触发提供了见解，并应为未来丝状病毒疫苗的研发提供参考。
