Department of Chemistry, Washington University in St. Louis, St. Louis, MO, 63130, USA.
Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, 63110, USA.
J Am Soc Mass Spectrom. 2017 Nov;28(11):2515-2518. doi: 10.1007/s13361-017-1782-0. Epub 2017 Sep 5.
Plasmodium vivax Duffy Binding Protein (PvDBP) is a promising vaccine candidate for P. vivax malaria. Recently, we reported the epitopes on PvDBP region II (PvDBP-II) for three inhibitory monoclonal antibodies (2D10, 2H2, and 2C6). In this communication, we describe the combination of native mass spectrometry and ion mobility (IM) with collision induced unfolding (CIU) to study the conformation and stabilities of three malarial antigen-antibody complexes. These complexes, when collisionally activated, undergo conformational changes that depend on the location of the epitope. CIU patterns for PvDBP-II in complex with antibody 2D10 and 2H2 are highly similar, indicating comparable binding topology and stability. A different CIU fingerprint is observed for PvDBP-II/2C6, indicating that 2C6 binds to PvDBP-II on an epitope different from 2D10 and 2H2. This work supports the use of CIU as a means of classifying antigen-antibody complexes by their epitope maps in a high throughput screening workflow. Graphical Abstract ᅟ.
恶性疟原虫杜菲结合蛋白（PvDBP）是恶性疟原虫疟疾的有前途的疫苗候选物。最近，我们报道了 PvDBP 区域 II（PvDBP-II）上针对三种抑制性单克隆抗体（2D10、2H2 和 2C6）的表位。在本通讯中，我们描述了将天然质谱法和离子淌度（IM）与碰撞诱导解折叠（CIU）相结合，以研究三种疟原虫抗原-抗体复合物的构象和稳定性。这些复合物在碰撞激活时会发生构象变化，这取决于表位的位置。与抗体 2D10 和 2H2 结合的 PvDBP-II 的 CIU 模式非常相似，表明结合拓扑结构和稳定性相当。对于 PvDBP-II/2C6，观察到不同的 CIU 指纹，表明 2C6 结合 PvDBP-II 的表位与 2D10 和 2H2 不同。这项工作支持使用 CIU 作为通过表位图谱对高通量筛选工作流程中的抗原-抗体复合物进行分类的一种手段。
