VITAMIN K-DEPENDENT PLASMA PROTEINS

这项研究有三个与以下相关的总体目标 了解血液聚集的物理和动力学性质 凝固级联。首先是要了解 钙中的维生素K依赖氨基酸、伽玛-羧基谷氨酸 结合和蛋白-膜结合。蛋白质的结构是 参与并改变钙离子结合的将是 用核磁共振和稀土取代实验进行了研究 利用维生素K依赖的膜结合部分 凝血酶原。镧系元素的实验还将广泛使用 荧光技术。蛋白质-膜界面的结构 将通过测量动态和平衡属性来研究 蛋白质-膜结合及用镧系元素替代钙 以及确定被检测到的复合体的各种距离和变化 荧光技术。第二个主要领域是结构和 含有一种以上蛋白质的膜复合体的功能。这个 最初的假设是维生素的膜结合部位 依赖钾的蛋白质作为整体结合的一部分发挥作用 互动。也就是说，这些蛋白质通常同时与一种 膜加上至少一种其他膜结合蛋白。特定的 待研究膜表面的蛋白质-蛋白质复合体包括： 蛋白S与蛋白C(A)和补体C4结合蛋白。其他 例子包括含有因子Va、因子VIIIa或 血栓调节蛋白。它们的平衡、动力学和水动力方面 将测量相互作用以确定这些蛋白质是否与 当它们被膜束缚时，它们相互作用。准弹性光散射 将使用光散射和各种荧光技术。蛋白 结合到磷脂单分子层也将被用来记录 蛋白质-脂类缔合的性质。第三个研究领域 涉及凝血收缩阶段的蛋白质。至少有一部分 这些蛋白质结合到脂膜上并经历激活。各种不同的 上述蛋白质-脂质缔合的性质将是 测量以帮助理解绑定所涉及的物理作用力。 对因子激活动力学的分析将与 蛋白质-脂质结合，试图了解表面如何影响这一点 动力学事件。这些研究应该会增加我们对 蛋白质-膜相互作用的一般情况以及这种相互作用是如何 专门负责提高血液凝固率 进程。

This research has three general objectives that are related to understanding the physical and kinetic properties of assembling the blood coagulation cascade. The first is to understand the function of the vitamin K-dependent amino acid, Gamma-carboxyglutamic acid in calcium binding and protein-membrane association. The protein structures that are involved in, and change as a result of, calcium ion binding will be investigated by use of nmr and lanthanide substitution experiments utilizing the vitamin K-dependent, membrane-binding portion of prothrombin. The lanthanide experiments will also make extensive use of fluorescence techniques. The structure at the protein-membrane interface will be studied by measuring dynamic and equilibrium properties of protein-membrane association and by substitution of lanthanides for calcium and determining various distances and changes in the complex detected by fluorescence techniques. The second major area is the structure and function of membrane complexes containing more than one protein. The initial hypothesis is that the membrane-binding site of the vitamin K-dependent proteins functions as a portion of an overall binding interaction. That is, these proteins normally bind simultaneously to a membrane plus at least one other membrane-bound protein. Specific protein-protein complexes on the membrane surface to be studied include: protein S with protein C(a) and with complement C4-binding protein. Other examples include protein C(a) with factor Va, factor VIIIa or thrombomodulin. Equilibrium, dynamic and hydrodynamic aspects of these interactions will be measured to determine if the proteins associate with each other while they are membrane bound. Light scattering, quasielastic light scattering and various fluorescence techniques will be used. Protein binding to phospholipid monolayers will also be used to document the properties of the protein-lipid associations. The third area of study involves proteins of the contract phase of coagulation. At least some of these proteins bind to lipid membranes and undergo activation. The various properties of the protein-lipid associations describe above will be measured to help understand the physical forces involved in binding. Analysis of the kinetics of factor activation will be correlated with protein-lipid binding to try to understand how the surface influences this kinetic event. These studies should increase our knowledge of protein-membrane interactions in general and how such interactions are specifically responsible for enhancing the rates of the blood coagulation process.