STRUCTURAL STUDIES ON FIBRINOGEN AND FIBRIN

该提案描述了一组旨在实现 纤维蛋白原和纤维蛋白的结构的详细探索，信息 任何对血栓形成和破坏的真正理解都必须 休息 该计划要求隔离 人纤维蛋白原分子，包括“卷曲螺旋”结构域间连接物， α-链突起，以及片段D和 E. 我们还计划合成两个含二硫键的结构， 分子的关键部分，其结构将保持不确定， 制备并比较合成异构体。 另一项工作涉及 亲和标记的两个不同的聚合位点位于 末端域 该提案还规定， 表现出缺陷的变异人纤维蛋白原的表征 聚合，特别注意那些表现出 某些合成肽的结合减弱， 模拟关键供体结合位点的Gly-Pro-Arg和Gly-His-Arg。 的方法 描述了从杂合混合物中纯化变体分子， 用于鉴定和表征来自这些肽的变体肽的方案 纤维蛋白原 最后，该项目规定完成氨基酸 原始脊椎动物（七鳃鳗）的纤维蛋白原序列， 可以鉴定分子的结构上最关键的部分; 在其他分子系统的基础上，有很好的证据表明， 在进化过程中蛋白质的保守性，而不太重要的功能， 彻底改变 从所有这些实验中得到的信息 在很大程度上依赖于纤维蛋白形成、稳定和纤维蛋白溶解的现象， 都有深刻的临床反映。

This proposal describes a concerted set of experiments directed towards a detailed exploration of the structures of fibrinogen and fibrin, information upon which any genuine understanding of clot formation and destruction must rest. The plan calls for the isolation of various domains and subdomains of the human fibrinogen molecule, including the "coiled coil" interdomainal connectors, the alpha-chain protuberances, and various derivative forms of fragments D and E. We also plan to synthesize two disulfide-containing structures corresponding to key parts of the molecule whose structures will remain equivocal until synthetic isomers are made and compared. Another undertaking involves the affinity-labeling of the two different polymerization sites located on the terminal domains. The proposal also provides for the identification and characterization of variant human fibrinogens that exhibit defective polymerization, particular attention being paid to those variants that show diminished binding of certain synthetic peptides involving the sequences Gly-Pro-Arg and Gly-His-Arg that simulate key donor binding sites. A method for purifying the variant molecules from heterozygous mixtures is described and a protocol laid out for identifying and characterizing variant peptides from these fibrinogens. Finally, the project provides for the completion of the amino acid sequence of a fibrinogen from a primitive vertebrate (the lamprey) in order that the structurally most critical parts of the molecule may be identified; there is good evidence on the basis of other molecular systems that the important parts of proteins are conserved during evolution whereas less critical features may change radically. The information derived from all these experiments bears heavily on the phenomena of fibrin formation, stabilization and fibrinolysis, all of which have profound clinical reflections.