CRYSTAL STRUCTURE OF FIBRINOGEN FRAGMENTS

纤维蛋白原是纤维蛋白的前体，血液是 凝块是由。它是一种大分子糖蛋白。 由两对三条不同的多肽链组成的。一个 全分子的高分辨X射线结构还有待进一步研究 获得。最近，我们确定了主体的结构 人纤维蛋白原的蛋白水解性片段，D片段，也是 凝血因子XIII交联人纤维蛋白的相应片段 (双D)。我们还成功地将这两种物质共结晶 具有两个不同合成肽的实体，这两个合成肽与 在纤维蛋白原片段E部分发现聚合旋钮。全 告诉我们，我们已经能够获得七种不同的(但接近的) 相关)结构。各种结构的分辨率范围 从2.9到2.3 E.已经发现了一些构象变化 与纤维蛋白原早期阶段的不同步骤相对应 到纤维蛋白转化。我们也有重要的络合物的晶体 被称为“D2E”。虽然晶体很小，但我们希望 我们将能够收集足够高质量的足够数据 片段E部分将在分子中显现 仅替换解决方案。

Fibrinogen is the precursor of fibrin, the material of which blood clots are composed. It is a large molecular weight glycoprotein composed of two pairs of three non-identical polypeptide chains. A high resolution X-ray structure of the whole molecule has yet to be obtained. Recently, we determined the structures of the principal proteolytic fragment of human fibrinogen, fragment D, and also of the corresponding fragments from factor XIII crosslinked human fibrin (double-D). We have also managed to co-crystallize both of these entities with two different synthetic peptides that correspond to the polymerization knobs found on the fragment E part of fibrinogen. All told, we have been able to obtain seven different (but closely related) structures. The resolution of the various structures ranges from 2.9 to 2.3 E. A number of conformational changes have been found that correspond to various steps in the early stages of the fibrinogen to fibrin conversion. We also have crystals of the important complex known as "D2E." Although the crystals are small, it is our hope that we will be able to collect sufficient data of a high enough quality that the fragment E portion will be apparent with a molecular replacement solution alone.