MODULATION OF VON WILLEBRAND FACTOR BINDING FACTOR VIII

血管性血友病因子结合因子 VIII 的调节

• 批准号: 2459907
• 负责人: ANA V BENDETOWICZ
• 金额: $ 0.77万
• 依托单位: BRIGHAM AND WOMEN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/2459907
• 关键词: blood coagulation; blood coagulation disorders; coagulation factor VIII; disulfide bond; human tissue; intermolecular interaction; von Willebrand factor

The goals of the research proposed are first, to characterize the effect of plasma on factor VIII binding to von Willebrand factor (vWF) and identify a vWF-binding protein that inhibits factor VIII binding. Aspects such as affinity and stoichiometry for the interaction of factor VIII with pure vWF vs. vWF reconstituted in plasma will be studied. It will also be determined whether the putative plasma vWF-binding protein decreases the rate of factor VIII association with vWF or increases the rate of dissociation from vWF. The importance of these findings relates to a better understanding of modulation of factor VIII levels in pregnancy, inflammation and DDAVP therapy, as well as secondary factor VIII deficiency. Until now, the explanation of secondary factor VIII deficiency is limited to a "decreased binding" of factor VIII to vWF due to specific mutations in the factor VIII binding region of vWF. Understanding binding kinetics of the association of another protein with vWF will help to better characterize secondary factor VIII deficiency. The second goal of this proposal is to identify structural features of vWF that influence the interaction with factor VIII. To accomplish this aim, we will focus on studies to characterize the role of inter and intrasubunit vWF disulfide bonds on factor VIII binding. We will conduct equilibrium and kinetics studies that will compare binding of factor VIII to multimeric vWF and mutant vWF incapable of multimer formation. In addition, we will construct vWF mutants based on mutations found in a patient with secondary factor VIII deficiency (R9lQ and C268S), and investigate what is the role of vWF Cys 268 on factor VIII binding. vWF regulates the levels of factor VIII, which has been shown to increase its plasma levels in deep venous thrombosis (DVT). Our results may alter the understanding of pathogenesis of DVT.

提出的研究目标是，首先，表征效果 血浆对因子VIII与血管性血友病因子（vWF）结合的影响， 鉴定抑制因子VIII结合的vWF结合蛋白。方面 例如因子VIII相互作用的亲和力和化学计量 将研究纯vWF与在血浆中重构的vWF。它将 还可以确定推定的血浆vWF结合蛋白是否 降低因子VIII与vWF的结合率或增加 从vWF解离的速率。这些发现的重要性与 更好地理解凝血因子VIII水平的调节， 妊娠、炎症和DDAVP治疗，以及次要因素 VIII缺乏症。到目前为止，对第八因子的解释 缺乏仅限于因子VIII与vWF的“结合减少”， vWF的因子VIII结合区的特定突变。 了解另一种蛋白质与 vWF将有助于更好地表征继发性凝血因子VIII缺乏症。 本建议的第二个目标是确定 vWF影响与因子VIII的相互作用。为了实现这一 目的，我们将集中研究，以表征的作用， 亚基内vWF二硫键对因子VIII结合的影响。我们会进行 平衡和动力学研究将比较因子VIII的结合 多聚体vWF和不能形成多聚体的突变体vWF。在 此外，我们将构建vWF突变体的基础上发现的突变， 患有继发性因子VIII缺乏症（R91Q和C268S）的患者，以及 研究vWF Cys 268对因子VIII结合的作用。VWF 调节因子VIII的水平，这已被证明可以增加其 深静脉血栓形成（DVT）的血浆水平。我们的研究结果可能会改变 了解DVT的发病机制。