Regulation of von Willebrand Factor - platelet binding by Force and Interdomain I

项目摘要 动脉血栓形成发生在高液体流量的条件下，并通过结合 血小板通过其受体糖蛋白Ib(GPIB)与称为von Willebrand的血浆蛋白结合 通过A1结构域的因子(VWF)。这一过程通常被下调，以防止 自发性粘连和血栓形成，但可被高剪应力激活。建议数 工作将检验这样的假设，即GPIB与A1的结合被邻近的 VWF内的结构域或侧翼区域，使VWF显示域间自动抑制。会的 也要测试与高剪应力相关的机械力激活的假设 通过将这些调节区从A1结构域拉出而与血小板结合，以解除自身- 抑制力。需要检验的最后一个假设是，增加自发性的条件 血小板与VWF的结合，包括2B型von Willebrand病，是通过破坏 正常的域间自动抑制。VWF中的监管领域和元素将是 通过克隆VWF的不同区域并测定两者的黏附行为来鉴定 可溶的和表面固定的分子。机械力和剪应力对材料力学性能的影响 这一规定将使用原子力显微镜和微流控技术在 以定向的方式固定分子。

Project Summary Arterial thrombosis occurs in conditions of high fluid flow and is mediated by the binding of platelets via their receptor Glycoprotein Ib (GPIb) to the plasma protein called von Willebrand Factor (VWF) via the A1 domain. This process is normally down-regulated to prevent spontaneous adhesion and thrombosis, but is activated by high shear stress. The proposed work will test the hypothesis that binding of GPIb to A1 is down-regulated by the neighboring domains or flanking regions within VWF, so that VWF displays interdomain auto-inhibition. It will also test the hypothesis that mechanical force associated with high shear stress activates platelet binding by pulling these regulatory regions away from the A1 domain to relieve the auto- inhibition. The final hypothesis to be tested is that conditions that increase the spontaneous binding of platelets to VWF, including type 2B von Willebrand disease, do so by damaging the normal interdomain auto-inhibition. Regulatory domains and elements within VWF will be identified by cloning different regions of VWF and determining the adhesive behavior of both soluble and surface-immoblized molecules. The effect of mechanical force and shear stress on this regulation will be determined using an atomic force microscope and microfluidics after immobilizing the molecules in an oriented fashion.