Structural insights into triple-helical collagen cleavage by matrix metalloproteinase 1
Structural insights into triple-helical collagen cleavage by matrix metalloproteinase 1
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DOI：
10.1073/pnas.1204991109
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发表时间：
2012-07-31
影响因子：
11.1
通讯作者：
Nagase, Hideaki
中科院分区：
文献类型：
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作者：
Manka, Szymon W.;Carafoli, Federico;Nagase, Hideaki
基质金属蛋白酶 (MMP) 家族的胶原酶在形态发生、组织修复和人类疾病中发挥着重要作用，但它们如何识别和裂解胶原三螺旋尚不完全清楚。在这里，我们报告了催化失活的 MMP-1 突变体 (E200A) 通过其催化结构域和血红素结合蛋白结构域的协同作用与胶原蛋白的温度依赖性结合。通过筛选胶原蛋白工具包肽库和氢/氘交换来绘制两个分子之间的接触图。与三螺旋胶原肽结合的 MMP-1(E200A) 的晶体结构揭示了 115 埃长的三螺旋与两个 MMP-1 结构域之间的广泛相互作用。血红素结合蛋白结构域中的外部位点将亮氨酸 10 残基 C 端与易断键结合，对于胶原蛋白溶解至关重要，并且代表了抑制剂开发的独特靶点。易裂键在结晶复合物中的水解位置不正确。通过胶原同源三聚体的轴向旋转，可以轻松模拟有效的结合模式，而无需改变 MMP-1 结构或外部位点相互作用。酶的域间弯曲和最接近活性位点的胶原链的局部偏移，在底物的热松弛的促进下，可能导致胶原溶解的第一个过渡状态。
Collagenases of the matrix metalloproteinase (MMP) family play major roles in morphogenesis, tissue repair, and human diseases, but how they recognize and cleave the collagen triple helix is not fully understood. Here, we report temperature-dependent binding of a catalytically inactive MMP-1 mutant (E200A) to collagen through the cooperative action of its catalytic and hemopexin domains. Contact between the two molecules was mapped by screening the Collagen Toolkit peptide library and by hydrogen/deuterium exchange. The crystal structure of MMP-1(E200A) bound to a triple-helical collagen peptide revealed extensive interactions of the 115-angstrom-long triple helix with both MMP-1 domains. An exosite in the hemopexin domain, which binds the leucine 10 residues C-terminal to the scissile bond, is critical for collagenolysis and represents a unique target for inhibitor development. The scissile bond is not correctly positioned for hydrolysis in the crystallized complex. A productive binding mode is readily modeled, without altering the MMP-1 structure or the exosite interactions, by axial rotation of the collagen homotrimer. Interdomain flexing of the enzyme and a localized excursion of the collagen chain closest to the active site, facilitated by thermal loosening of the substrate, may lead to the first transition state of collagenolysis.