HUMAN BLOOD PLATELET GLYCOPROTEIN IB

人血血小板糖蛋白 IB

• 批准号: 3470943
• 负责人: ALAN M MICHELSON
• 金额: $ 9.63万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 1987
• 资助国家: 美国
• 起止时间: 1987-04-01 至 1992-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3470943
• 关键词: Wiskott Aldrich syndrome; adhesions; cell sorting; chemical binding; chromatography; coagulation factor VII; congenital blood protein disorder; electrophoresis; enzyme linked immunosorbent assay; glycoproteins; human tissue; immunoelectron microscopy; immunofluorescence technique; membrane activity; membrane proteins; monoclonal antibody; plasma; platelets; radioassay; thrombocytopathy

Platelet adhesion to damaged blood vessel walls is facilitated by the binding of von Willebrand factor (VWF) to platelet membrane glycoprotein Ib (GPIb). This research proposal is a study of the biochemistry, cell physiology, and clinical significance of the GPIb receptor for VWF. The specific aims of this research program are: 1) Biochemistry: Characterize the binding site for VWF on GPIb. We have recently demonstrated that glycocalicin, a proteolytic fragment of GPIb, contains the VWF binding site. We now propose to characterize the binding site for VWF on glycocalicin by assessing digestion products of purified glycocalicin in assays developed to test glycocalicin/VWF binding. 2) Cell Physiology: Test the hypothesis that the GPIb receptor for VWF is processed from the interior of the platelet to the platelet surface and thence into the plasma. New methods have been developed which utilize a monoclonal antibody to quantify the GPIb receptor for VWF: a) inside the platelet (an enzyme-linked immunosorbent assay (ELISA) of the aqueous phase of Triton X-114 solubilized platelets), b) on the platelet surface (fluorescence-activated cell sorting (FACS)), and c) in the plasma (ELISA). Changes in these receptor pools will be determined after activation of washed platelets and storage of platelet concentrates. 3) Clinical significance: Investigate the GPIb defect in inherited platelet disorders. i) Wiskott-Aldrich syndrome (WAS): Preliminary studies with FACS have suggested tht patients with WAS have two subpopulations of platelets: one GPIb-positive and the other GPIb-negative. We now propose to characterize the GPIb defect in WAS patients and carriers. ii) Bernard-Soulier syndrome (BSS): BSS platelets are known to lack surface GPIb receptors for VWF. In order to clarify the underlying defect in BSS, the intraplatelet and plasma pools of this receptor will be analyzed. The results of these experiments are likely to provide a better understanding of the pathophysiology of platelet adhesion to damaged vessel walls. Clinically applicable knowledge which may be gained from this research program includes: changes in the adhesive properties of platelet concentrates during storage; metholology for diagnosis of carriers of WAS; and new insights into the pathogenesis of atherosclerosis, in light of the possible role of VWF in this disorder.

促进血小板粘附到受损血管壁 血管性血友病因子 (VWF) 与血小板膜的结合 糖蛋白 Ib (GPIb)。 本研究计划是一项研究 生物化学、细胞生理学和临床意义 VWF 的 GPIb 受体。 该研究计划的具体目标是： 1) 生物化学：表征 VWF 的结合位点 GPIb。 我们最近证明了糖运载蛋白，一种 GPIb 的蛋白水解片段，包含 VWF 结合 地点。 我们现在建议表征结合位点 通过评估消化产物对糖运载蛋白进行 VWF 纯化的糖运载蛋白用于测试开发的测定 糖运载蛋白/VWF 结合。 2) 细胞生理学：检验 GPIb 受体的假设 VWF 是从血小板内部加工到 血小板表面，然后进入血浆。 新方法 已开发出利用单克隆抗体 量化 VWF 的 GPIb 受体：a) 血小板内部 （酶联免疫吸附测定（ELISA） Triton X-114 溶解血小板的水相），b） 血小板表面（荧光激活细胞分选 (FACS))，和c) 血浆中(ELISA)。 这些变化 受体库将在洗涤激活后确定 血小板和浓缩血小板的储存。 3) 临床意义：研究GPIb缺陷 遗传性血小板疾病。 i) 威斯科特-奥尔德里奇综合征 (WAS)：FACS 的初步研究表明 WAS 患者有两个亚群 血小板：一种 GPIb 阳性，另一种 GPIb 阴性。 我们现在建议描述 WAS 中 GPIb 缺陷的特征 患者和携带者。 ii) Bernard-Soulier 综合征 (BSS)：已知 BSS 血小板缺乏表面 GPIb VWF 受体。 为了澄清潜在的缺陷 在 BSS 中，该受体的血小板内和血浆池 将被分析。 这些实验的结果可能会提供更好的结果 了解血小板粘附的病理生理学 损坏的容器壁。 临床适用的知识可能 从该研究计划中获得的成果包括： 浓缩血小板在储存过程中的粘附特性； WAS 携带者的诊断方法；和新的见解 探讨动脉粥样硬化的发病机制 VWF 在这种疾病中的作用。