STRUCTURAL SUDIES ON FIBRINGEN AND FIBRIN

两个压倒一切的问题统一了纤维蛋白原-纤维蛋白领域的所有工作者： 纤维蛋白聚合物中的纤维蛋白(原)单元是如何包装的？ 是什么力量把他们维系在一起？我们正在采取两种方法来 这些问题都是基于蛋白质进化上的相互依赖 结构和功能，另一种是基于仿制的合成肽 该系统最保守的特征。与此同时，我们正在 自然对脊椎动物血液凝结的方式和时间感兴趣 发明了“将军”一词。我们的建议是基于这样一个概念，即只有当我们 了解一个系统的历史，我们就可以智能地操纵它。 具体目标包括进一步表征来自 七鳃鳗，现存最原始的脊椎动物，也是最原始的 一种已知具有凝血酶凝固性纤维蛋白原分子的生物。我们计划 为了完成β链和阿尔法链克隆的cdna序列，如 以及对多肽结合和纤维蛋白聚合的继续研究。 从这些研究中获得的知识将应用于两个不同的 王国。首先，哺乳动物和七鳃鳗纤维蛋白原具有的特征 共同之处必须是发挥作用的关键，正如它们曾经被证明的那样 保存了4亿多年。我们计划合成最多的 严格保守纤维蛋白原分子的一部分，以便识别 聚合和其他相互作用的特定位置。第二，特色 七鳃鳗和哺乳动物纤维蛋白原的共同点也是最有可能 存在于更原始的生物中，其中纤维蛋白原尚未出现 找到了。我们打算使用这些特征的遗传等价物(即， 适当的限制片段和合成寡核苷酸)进行筛选 原脊索动物和无脊椎动物的基因组文库 被认为与脊椎动物有最密切的关系。的关注点 搜索将在外显子或区域等价物上进行，这可能是 在建造门型时从不同的来源组装 纤维蛋白原分子。这项研究还包括寻找 通常被认为是排他性的其他血浆蛋白的先行基因 对脊椎动物，包括白蛋白、转铁蛋白、铜蓝蛋白和 α-2-巨球蛋白。

Two overriding questions unify all workers in the fibrinogen-fibrin field: how are the fibrin(ogen) units packed in the fibrin polymer, and what are the forces that hold them together? We are taking a twofold approach to these problems, one based on the evolutionary interdependence of protein structure and function, the other based on synthetic peptides patterned on the most conserved features of the system. At the same time we are naturally interested in how and when vertebrate blood coagulation in general was invented. Our proposal is based on the notion that only if we understand the history of a system can we intelligently manipulate it. Specific goals include further characterization of fibrinogen from the lamprey, the most primitive vertebrate extant and the most primitive creature known to have a thrombin-clottable fibrinogen molecule. We plan to complete the cDNA sequences of clones for the beta and alpha chains, as well as continue studies on peptide binding and fibrin polymerization. Knowledge gained from these studies will be applied in the two different realms. First, those features that mammalian and lamprey fibrinogens have in common must be vital to function, as evidenced by their having been conserved for over 400 million years. We plan to synthesize the most rigorously conserved parts of the fibrinogen molecule in order to identify specific sites for polymerization and other interactions. Second, features common to lamprey and mammalian fibrinogens are also those most likely to exist in even more primitive creatures, among whom fibrinogen has yet to be found. We intend to use the genetic equivalents of those features (i.e., appropriate restriction fragments and synthetic oligonucleotides) to screen genomic libraries prepared from protochordates and those invertebrates thought to be most closely related to the vertebrate line. The focus of the search will be on exon or domainal equivalents that may have been assembled from diverse sources in the construction of the portotype fibrinogen molecule. The study also encompasses a search for the antecedent genes of other plasma proteins usually thought to be exclusive to vertebrates, including albumin, transferrin, ceruloplasmin and alpha-2-macroglobulin.