Centre for Structural Systems Biology (CSSB), DESY and European Molecular Biology Laboratory Hamburg, Notkestrasse 85, D-22607, Hamburg, Germany.
Centre for Structural Systems Biology (CSSB) and Karolinska Institutet VR-RÅC, Notkestrasse 85, D-22607, Hamburg, Germany.
Nat Commun. 2020 Nov 4;11(1):5588. doi: 10.1038/s41467-020-19204-y.
The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Therapeutic neutralizing antibodies constitute a key short-to-medium term approach to tackle COVID-19. However, traditional antibody production is hampered by long development times and costly production. Here, we report the rapid isolation and characterization of nanobodies from a synthetic library, known as sybodies (Sb), that target the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein. Several binders with low nanomolar affinities and efficient neutralization activity were identified of which Sb23 displayed high affinity and neutralized pseudovirus with an IC of 0.6 µg/ml. A cryo-EM structure of the spike bound to Sb23 showed that Sb23 binds competitively in the ACE2 binding site. Furthermore, the cryo-EM reconstruction revealed an unusual conformation of the spike where two RBDs are in the 'up' ACE2-binding conformation. The combined approach represents an alternative, fast workflow to select binders with neutralizing activity against newly emerging viruses.
冠状病毒 SARS-CoV-2 是引发当前 COVID-19 大流行的病原体。治疗性中和抗体是应对 COVID-19 的一种关键的中短期手段。然而，传统的抗体生产受到开发时间长和生产成本高的限制。在这里，我们报告了一种源自合成文库（称为 sybodies，Sb）的纳米抗体的快速分离和鉴定，这些纳米抗体针对 SARS-CoV-2 刺突蛋白的受体结合域（RBD）。鉴定出了一些具有低纳摩尔亲和力和高效中和活性的结合物，其中 Sb23 表现出高亲和力，能中和假病毒，IC 为 0.6μg/ml。与 Sb23 结合的 Spike 的冷冻电镜结构表明，Sb23 在 ACE2 结合位点上竞争性结合。此外，冷冻电镜重建揭示了 Spike 的一种不寻常构象，其中两个 RBD 处于“向上”的 ACE2 结合构象。这种联合方法代表了一种替代的、快速的工作流程，可以选择针对新出现病毒具有中和活性的结合物。
Zotero 插件
