Design of a Novel Fab‐Like Antibody Fragment with Enhanced Stability and Affinity for Clinical use
Design of a Novel Fab‐Like Antibody Fragment with Enhanced Stability and Affinity for Clinical use
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设计新型 Fab 样抗体片段，具有增强的稳定性和亲和力，适合临床使用
DOI：
10.1002/smtd.202100966
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发表时间：
2022
期刊：
影响因子：
12.4
通讯作者：
Tianlei Ying
中科院分区：
文献类型：
--
作者：
Chunyu Wang;Jiaxu Hong;Zhenlin Yang;Xujiao Zhou;Yuhan Yang;Yu Kong;Binfan Chen;Huifang Wu;Bin‐Zhi Qian;Dimiter S. Dimitrov;Xingtao Zhou;Yanling Wu;Tianlei Ying
随着重组单抗在人类医学中的应用越来越受到人们的关注，人们迫切需要尺寸更小、稳定性更好的工程化单抗片段来克服目前临床应用的局限性。在这里，描述了一种新的Fab样抗体片段，该抗体片段是通过基于电子计算机的工程方法产生的，其中Fab的CH1和CL结构域被IgG1CH3结构域取代。这种被命名为FabCH3的结构保持了抗体的自然N端和C端，可以在细菌细胞中高水平表达，重要的是，当在中硫蛋白特异的Fab m912和血管内皮生长因子A(VEGFA)特异的Fab ranibizumab中测试时，它比亲本Fab表现出更高的稳定性和亲和力。测定了m912FabCH3和m912Fab的高分辨晶体结构，对比分析表明，在FabCH3的恒定域和互补决定区都有更多的刚性结构，说明其稳定性和亲和力增强。总体而言，本报告中描述的稳定的FabCH3为设计具有更高稳定性和抗原结合亲和力的Fab样抗体片段提供了一个通用平台，可用作一类独特的抗体疗法。
With increasing interest in applying recombinant monoclonal antibodies (mAbs) in human medicine, engineered mAb fragments with reduced size and improved stability are in demand to overcome current limitations in clinical use. Herein, a novel Fab‐like antibody fragment generated via an in silico‐based engineering approach where the CH1 and CL domains of Fab are replaced by the IgG1 CH3 domains is described. This construct, designated as FabCH3, maintains the natural N‐terminus and C‐terminus of IgG antibody, can be expressed at a high level in bacterial cells and, importantly, exhibits much higher stability and affinity than the parental Fab when tested in a mesothelin‐specific Fab m912, as well as a vascular endothelial growth factor A (VEGFA)‐specific Fab Ranibizumab (in vivo). The high‐resolution crystal structures of m912 FabCH3 and m912 Fab are determined, and the comparative analysis reveals more rigid structures in both constant domains and complementarity‐determining regions of FabCH3, explaining its enhanced stability and affinity. Overall, the stabilized FabCH3 described in this report provides a versatile platform for engineering Fab‐like antibody fragments with higher stability and antigen‐binding affinity that can be used as a distinct class of antibody therapeutics.