Chemistry Department, York University, 4700 Keele Street, Toronto, ON M3J 1P3, Canada.
The Centre for Research in Mass Spectrometry, York University, Toronto, ON M3J1P3, Canada.
Biochemistry. 2020 Aug 4;59(30):2776-2781. doi: 10.1021/acs.biochem.0c00308. Epub 2020 Jul 21.
The success of bevacizumab (Avastin), a monoclonal antibody (mAb) anticancer drug targeting vascular endothelial growth factor A (VEGF-A), has motivated the development of biosimilars. Establishing target epitope similarity using epitope mapping is a critical step in preclinical mAb biosimilar development. Here we use time-resolved electrospray ionization hydrogen-deuterium exchange (HDX) mass spectrometry to rapidly compare the epitopes of commercial Avastin and a biosimilar in preclinical development (ApoBev) on an extended construct of VEGF-A. The Avastin and ApoBev epitopes determined in our experiments agree with each other and with the known epitope derived from the Avastin Fab domain/truncated VEGF co-crystal structure. However, subtly different allosteric effects observed exclusively at short (millisecond) HDX labeling times may reflect a slightly different binding mode for ApoBev.
贝伐珠单抗（阿瓦斯汀）是一种靶向血管内皮生长因子 A（VEGF-A）的单克隆抗体（mAb）抗癌药物，其成功促使了生物类似药的发展。使用表位作图来建立靶表位相似性是临床前 mAb 生物类似药开发的关键步骤。在这里，我们使用时间分辨电喷雾电离氢-氘交换（HDX）质谱法，在 VEGF-A 的扩展构建体上快速比较商业阿瓦斯汀和临床前开发的生物类似药（ApoBev）的表位。我们实验中确定的阿瓦斯汀和 ApoBev 表位彼此一致，并且与源自阿瓦斯汀 Fab 结构域/截短 VEGF 共结晶结构的已知表位一致。然而，仅在短（毫秒）HDX 标记时间观察到的微妙不同的变构效应可能反映了 ApoBev 的略微不同的结合模式。
