STRUCTURAL STUDIES ON FIBRINOGEN AND FIBRIN

这项提案描述了一系列协调一致的实验，旨在 详细探索纤维蛋白原和纤维蛋白的结构，信息 任何对血栓形成和破坏的真正了解都必须建立在 好好休息。该计划要求隔离网络的各个域和子域 人类纤维蛋白原分子，包括“盘绕”的域间连接器， α链突起，以及碎片D和D的各种衍生形式 E.我们还计划合成两个相应的含二硫化物的结构 其结构将保持模棱两可的分子关键部分，直到 合成了异构体，并进行了比较。另一项承诺涉及 两种不同聚合点的亲和标记 终端域。该提案还规定了身份识别和 具有缺陷的变异型人纤维蛋白原的特性 聚合反应，特别关注那些表现出 涉及序列的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。一种方法，该方法 描述了从杂合混合物中提纯变异分子的方法和一种 为从这些多肽中识别和表征变异多肽而制定的协议 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，以便 可以确定分子结构上最关键的部分；有 有力的证据证明了其他分子体系的重要组成部分 的蛋白质在进化过程中是保守的，而不那么关键的特征可能 从根本上改变。从所有这些实验中获得的信息与 非常重视纤维蛋白的形成、稳定和纤溶现象， 所有这些都有深刻的临床反思。

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.