CRYSTALLOGRAPHIC STRUCTURES OF KRINGLES AND GLA-DOMAINS

这项工作的长期目标是将一些 血凝级联事件在三维空间中的分布 结构基础，在纤溶方面也是如此； 生命的进程直接依赖于适当的 执行这两个功能。这些目标是要实现的 通过测定一些化合物的晶体结构 参与这一过程的分子，然后扩展 将信息传递给一个更大的密切相关的群体 用结晶学进行分子的计算机图形建模 坐标、高场核磁共振观测、静电 计算和能量最小化优化。我们已经这么做了 通过对He Lys模型的建模，验证了该方法的可行性 几种纤维蛋白结合部位的亚位点 Kringle结构，包括组织纤溶酶原激活物(TPA)， 基于凝血酶原片段1的结构。我们计划 用结构展开观察到的kringle结构库 纤溶酶原和凝血酶原片段K4的测定。 此后，我们将对剩余的五个kringle进行建模 不同血液蛋白与37个高度保守的K4环 载脂蛋白(A)。通过扩展的Kringle库，Kringle- 多个Kringle蛋白中的Kringle堆积相互作用将是 基于在四种不同晶体结构中的堆积进行近似， 计算机图形学和片段1-2的结构。 凝血酶原的GLA结构域存在于其他六种蛋白质中 凝血和钙离子共同作用于膜结合 这些分子中。大分子膜复合体增强 以一种壮观的方式催化。我们即将解决这个问题 发生构象变化的Ca+2-片段1的结构 膜结合的过渡性要求。结构将是 用于对其他GLA域进行建模，这些域表现得更好 保护而不是kringles。GLA-Ca~(2+)-磷脂相互作用 会从结晶学的结合研究中固定下来 有机磷酸盐及其构象变化的动力学 将通过确定Mg+2-片段的结构来实现 1显示了不同的构象，将用 骨GLA蛋白--也将是一种新的Ca+2-GLA 结合结构域。

The long range objectives of this work are to place some of the events of the blood coagulation cascade on a three dimensional structural basis and to do likewise for aspects of fibrinolysis; the very processes of life are directly dependent upon the proper execution of both of these functions. The goals are to be achieved by determining the crystallographic structures of a number of molecules involved in the processes and then extending the information to a much larger group of closely interrelated molecules by computer graphics modeling with crystallographic coordinates, high field NMR observations, electrostatic calculations and energy minimization refinements. We have already demonstrated the feasibility of this approach by modeling he Lys subsite of the fibrin binding site of several fibrin binding kringle structures, including tissue plasminogen activator (TPA), based on the structure of prothrombin fragment 1. We plan to expand the observed kringle structure library with the structure determination of K4 of plasminogen and prothrombin fragment 2. Thereafter, we will model the remaining eight kringles of five different blood proteins and the 37 highly conserved K4 kringles of apolipoprotein(a). With an expanded kringle library, kringle- kringle packing interactions in multiple kringle proteins will be approximated based on packing in four different crystal structures, computer graphics and the structure of fragment 1-2. The Gla-domain of prothrombin occurs in six other proteins of coagulation and along with Ca+2 is responsible for membrane binding of these molecules. The macromolecular membrane complexes enhance catalysis in a spectacular way. We are on the verge of solving the structure of Ca+2-fragment 1 which has undergone the conformational transition demanded of membrane binding. The structure will be used to model the other Gla-domains that show even greater conservation than kringles. The Gla-Ca+2-phospholipid interaction will be fixed from crystallographic binding studies with small organic phosphates and the dynamics of the conformational changed will be approached by determining the structure of Mg+2-fragment 1 which displays a different conformation will be investigated with bone Gla protein which will also be a new example of a Ca+2-Gla binding domain.