Active-site MMP-selective antibody inhibitors discovered from convex paratope synthetic libraries
Active-site MMP-selective antibody inhibitors discovered from convex paratope synthetic libraries
复制标题
DOI：
10.1073/pnas.1609375114
复制
发表时间：
2016-12-27
影响因子：
11.1
通讯作者：
Ge, Xin
中科院分区：
文献类型：
--
作者：
Dong Hyun Nam;Rodriguez, Carlos;Ge, Xin
蛋白酶是常见的药理学靶点，其抑制剂在多种病理学中是有价值的药物。然而，催化机制和活性位点折叠在很大程度上是保守的蛋白酶类，使选择性抑制剂的发展极具挑战性。在我们离开传统的策略，我们回顾了已知的骆驼抑制性抗体的结构，通过其异常长，凸形的互补位阻断酶的活性。我们合成了人Fab抗体文库（超过1.25 x 10（9）个个体变体），其携带延伸的23至27个残基的互补决定区（CDR）-H3区段。作为原理的证明，我们使用基质金属蛋白酶-14（MMP-14）的催化结构域作为诱饵，MMP-14是一种促癌蛋白酶和癌症中的药物靶点。在我们的筛选中，我们鉴定了20种结合剂，其中14种表现为MMP-14的有效和选择性抑制剂，而不是广泛特异性拮抗剂。具体地，Fab 3A 2以4.8 nM的高亲和力在活性口袋附近与MMP-14结合，并且在抑制蛋白酶切割活性方面类似地有效（9.7 nM）。我们认为，这里描述的凸互补位抗体库可以很容易地推广到许多其他酶的抗体抑制剂的设计。
Proteases are frequent pharmacological targets, and their inhibitors are valuable drugs in multiple pathologies. The catalytic mechanism and the active-site fold, however, are largely conserved among the protease classes, making the development of the selective inhibitors exceedingly challenging. In our departure from the conventional strategies, we reviewed the structure of known camelid inhibitory antibodies, which block enzyme activities via their unusually long, convex-shaped paratopes. We synthesized the human Fab antibody library (over 1.25 x 10(9) individual variants) that carried the extended, 23-to 27-residue, complementarity-determining region (CDR)-H3 segments. As a proof of principle, we used the catalytic domain of matrix metalloproteinase-14 (MMP-14), a promalignant protease and a drug target in cancer, as bait. In our screens, we identified 20 binders, of which 14 performed as potent and selective inhibitors of MMP-14 rather than as broad-specificity antagonists. Specifically, Fab 3A2 bound to MMP-14 in the vicinity of the active pocket with a high 4.8 nM affinity and was similarly efficient (9.7 nM) in inhibiting the protease cleavage activity. We suggest that the convex paratope antibody libraries described here could be readily generalized to facilitate the design of the antibody inhibitors to many additional enzymes.