TIMP-2 promotes activation of progelatinase a by membrane-type 1 matrix metalloproteinase immobilized on agarose beads
TIMP-2 promotes activation of progelatinase a by membrane-type 1 matrix metalloproteinase immobilized on agarose beads
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DOI：
10.1074/jbc.273.26.16098
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发表时间：
1998-06-26
影响因子：
4.8
通讯作者：
Seiki, M
中科院分区：
文献类型：
--
作者：
Kinoshita, T;Sato, H;Seiki, M
膜1型基质金属蛋白酶（MT 1-MMP）/MMP-14是细胞表面明胶酶A（proGelA）/proMMP-2的激活剂。然而，矛盾的是，表达MT 1-MMP的细胞激活proGelA需要金属蛋白酶组织抑制剂-2（TIMP-2），其是MT 1-MMP的抑制剂。在本研究中，在C末端具有FLAG标签序列的截短的MT 1-MMP（MT 1-F）被固定到琼脂糖珠（MT 1-F/B）上，并用于分析TIMP-2的作用。相比之下，TIMP-2在低浓度下促进MT 1-F/B对proGelA的加工，而在高浓度下抑制其加工。TIMP-2通过形成三分子复合物促进proGelA与珠上的MT 1-F结合，随后加工proGelA。TIMP-2的刺激作用在未被占据的MT 1-F仍然可用的条件下观察到。因此，三元复合物被认为是将底物浓缩到珠表面并将其呈递给相邻的游离MT 1-F的手段。
Membrane-type 1 matrix metalloproteinase (MT1-MMP)/MMP-14 is the activator of progelatinase A (proGelA)/proMMP-2 on the cell surface. However, it was a paradox that a tissue inhibitor of metalloproteinase-2 (TIMP-2), which is an inhibitor of MT1-MMP, is required for proGelA activation by the cells expressing MT1-MMP. In this study, a truncated MT1-MMP having a FLAG-tag sequence at the C terminus (MT1-F) was immobilized onto agarose beads (MT1-F/B) and used to analyze the role of TIMP-2, The proteolytic activity of MT1-F/B against a synthetic peptide substrate was inhibited by TIMP-2 in a dose-dependent manner. In contrast, TIMP-2 promoted the processing of proGelA by MT1-F/B at low concentrations and inhibited it at higher concentrations. TIMP-2 promoted the binding of proGelA to the MT1-F on the beads by forming a trimolecular complex, which was followed by processing of proGelA. A stimulatory effect of TIMP-2 was observed under conditions in which unoccupied MT1-F was still available. Thus, the ternary complex is thought to act as a means to concentrate the substrate to the bead surface and to present it to the neighboring free MT1-F.