Development of a DNA aptamer that binds to the complementarity-determining region of therapeutic monoclonal antibody and affinity improvement induced by pH-change for sensitive detection
Development of a DNA aptamer that binds to the complementarity-determining region of therapeutic monoclonal antibody and affinity improvement induced by pH-change for sensitive detection
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DOI：
10.1016/j.bios.2022.114027
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发表时间：
2022-02-01
影响因子：
12.6
通讯作者：
Ikebukuro, Kazunori
中科院分区：
文献类型：
--
作者：
Saito, Taro;Shimizu, Yutaka;Ikebukuro, Kazunori
治疗性单克隆抗体（mAb）是成功的生物医学;然而，其药代动力学和药效学的评价需要与血液中天然存在的人免疫球蛋白G高度特异性的区分。在这里，我们开发了一种新的抗独特型适体（称为A14#1），对抗血管内皮生长因子治疗性mAb贝伐单抗具有非凡的特异性。抗体-适体复合物的结构分析显示，A14#1的几个碱基仅识别贝伐珠单抗的互补决定区（CDR），从而有助于其非凡的特异性。由于预测贝伐珠单抗的CDR在弱酸性条件下带高度正电荷，并且DNA带负电荷，因此A14#1对贝伐珠单抗的亲和力在pH 4.7（K-D = 44 pM）下比在pH 7.4（K-D = 12 nM）下显著增加。因此开发了能够在pH 4.7下检测31 pM贝伐珠单抗的基于A14#1的电化学检测方法。A14#1可能作为贝伐单抗的新型配体用于治疗药物测量。
Therapeutic monoclonal antibodies (mAbs) are successful biomedicines; however, evaluation of their pharmacokinetics and pharmacodynamics demands highly specific discrimination from human immunoglobulin G naturally present in the blood. Here, we developed a novel anti-idiotype aptamer (termed A14#1) with extraordinary specificity against the anti-vascular endothelial growth factor therapeutic mAb, bevacizumab. Structural analysis of the antibody-aptamer complex showed that several bases of A14#1 recognized only the complementarity determining region (CDR) of bevacizumab, thereby contributing to its extraordinary specificity. As the CDR of bevacizumab is predicted to be highly positively charged under mildly acidic conditions and that DNA is negatively charged, the affinity of A14#1 to bevacizumab markedly increased at pH 4.7 (K-D = 44 pM) than at pH 7.4 (K-D = 12 nM). A14#1-based electrochemical detection method capable of detecting 31 pM of bevacizumab at pH 4.7 was thus developed. A14#1 could be potentially useful for therapeutic drug measurement as a novel ligand of bevacizumab.