The crystal structure of modified bovine fibrinogen
The crystal structure of modified bovine fibrinogen
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DOI：
10.1073/pnas.97.1.85
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发表时间：
2000-01-04
影响因子：
11.1
通讯作者：
Cohen, C
中科院分区：
文献类型：
--
作者：
Brown, JH;Volkmann, N;Cohen, C
在这里，我们报告了选择性蛋白水解牛纤维蛋白原的大约到4-ANGSTROM分辨率的晶体结构。止血中的这个关键成分是血浆中的细长的340 kDa糖蛋白，该血浆中凝血酶自组合激活后形成纤维蛋白凝块。晶体是不寻常的，因为它们由形成柔性丝的端到端粘结分子组成。我们已经可视化了该分子的整个盘绕线区域，该区域具有平面sigmoidal形状，在整个端到端的粘结丝中，该分子末端的主要聚合受体口袋面临着相同的方式，并且基于这种构型，我们已经开发了一种改进的二型型原纤维模型，这是Fiblirin in Fibrin in Fibrin in Fibrin in fibrin。在盘绕线圈区域的中间，纤溶酶敏感的片段是一个铰链，分子围绕该铰链采用不同的构象。该细分市场还包括盘绕线圈的三个链和四个链部分之间的边界，表明骨架上的位置固定了扩展的柔性alpha臂。我们建议分子中的柔性分支点可以帮助适应纤维蛋白血块结构的变异性。
Here we report the crystal structure at approximate to 4-Angstrom resolution of a selectively proteolyzed bovine fibrinogen. This key component in hemostasis is an elongated 340-kDa glycoprotein in the plasma that upon activation by thrombin self-assembles to form the fibrin clot. The crystals are unusual because they are made up of end-to-end bonded molecules that form flexible filaments. We have visualized the entire coiled-coil region of the molecule, which has a planar sigmoidal shape, The primary polymerization receptor pockets at the ends of the molecule face the same way throughout the end-to-end bonded filaments, and based on this conformation, we have developed an improved model of the two-stranded protofibril that is the basic building block in fibrin. Near the middle of the coiled-coil region, the plasmin-sensitive segment is a hinge about which the molecule adopts different conformations. This segment also includes the boundary between the three- and four-stranded portions of the coiled coil, indicating the location on the backbone that anchors the extended flexible A alpha arm. We suggest that a flexible branch point in the molecule may help accommodate variability in the structure of the fibrin clot.