A monoclonal antibody interferes with TIMP-2 binding and incapacitates the MMP-2-activating function of multifunctional, pro-tumorigenic MMP-14/MT1-MMP.
A monoclonal antibody interferes with TIMP-2 binding and incapacitates the MMP-2-activating function of multifunctional, pro-tumorigenic MMP-14/MT1-MMP.
复制标题
单克隆抗体会干扰 TIMP-2 结合，并使多功能促肿瘤 MMP-14/MT1-MMP 的 MMP-2 激活功能丧失能力。
DOI：
10.1038/oncsis.2013.44
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发表时间：
2013
期刊：
影响因子：
6.2
通讯作者：
Strongin,AY
中科院分区：
文献类型：
--
作者：
Shiryaev,SA;Remacle,AG;Golubkov,VS;Ingvarsen,S;Porse,A;Behrendt,N;Cieplak,P;Strongin,AY
基质金属蛋白酶（MMPs），特别是膜型1 (MT1)-MMP/MMP-14，是治疗恶性肿瘤的有希望的药物靶点。与多种MT1-MMP切割活性的小分子和蛋白泛抑制剂相比，小鼠9E8单克隆抗体仅针对细胞MT1-MMP的mmp -2激活功能，而不是针对MT1-MMP的一般蛋白水解活性和促迁移功能。此外，该抗体不会以任何可检测的方式与膜型(MT)-MMP家族的其他成员相互作用。这种选择性的机制尚不清楚。通过诱变、结合和活性分析以及硅模拟，我们已经证明9E8抗体识别mt -环结构，这是MT-MMPs特异性的8个残基插入，远离MT1-MMP活性位点。然而，9E8抗体与MT1-MMP环的结合阻止了组织金属蛋白酶抑制剂-2 （TIMP-2）与MT1-MMP的结合。因此，9E8抗体仅使timp -2依赖性mmp -2激活功能失能，而不是使人MT1-MMP的一般酶活性失能。我们确定的9E8抗体的特定功能直接支持了蛋白质抑制剂（TIMP-2）通过独特的膜栓机制在MMP-2激活中的重要作用，尽管这是矛盾的。在这一机制中，三分子MT1-MMPTIMP-2MMP-2复合物的形成是细胞捕获可溶性MMP-2前酶并将其转化为成熟的MMP-2酶所必需的。总之，了解9E8抗体特异性的结构要求可能为针对其他单个MMPs的抑制性抗体的重点设计铺平道路。
Matrix metalloproteinases (MMPs) and, especially membrane type 1 (MT1)-MMP/MMP-14, are promising drug targets in malignancies. In contrast with multiple small-molecule and protein pan-inhibitors of MT1–MMP cleavage activity, the murine 9E8 monoclonal antibody targets the MMP-2-activating function of cellular MT1–MMP alone, rather than the general proteolytic activity and the pro-migratory function of MT1–MMP. Furthermore, the antibody does not interact in any detectable manner with other members of the membrane type (MT)-MMP family. The mechanism of this selectivity remained unknown. Using mutagenesis, binding and activity assays, and modeling in silico, we have demonstrated that the 9E8 antibody recognizes the MT-loop structure, an eight residue insertion that is specific for MT–MMPs and that is distant from the MT1–MMP active site. The binding of the 9E8 antibody to the MT-loop, however, prevents tissue inhibitor of metalloproteinases-2 (TIMP-2) association with MT1–MMP. As a result, the 9E8 antibody incapacitates the TIMP-2-dependent MMP-2-activating function alone rather than the general enzymatic activity of human MT1–MMP. The specific function of the 9E8 antibody we determined directly supports an essential, albeit paradoxical, role of the protein inhibitor (TIMP-2) in MMP-2 activation via a unique membrane-tethered mechanism. In this mechanism, the formation of a tri-molecular MT1–MMPTIMP-2MMP-2 complex is required for both the capture of the soluble MMP-2 proenzyme by cells and then its well-controlled conversion into the mature MMP-2 enzyme. In sum, understanding of the structural requirements for the 9E8 antibody specificity may pave the way for the focused design of the inhibitory antibodies against other individual MMPs.