HUMAN BLOOD PLATELET GLYCOPROTEIN IB

人血血小板糖蛋白 IB

• 批准号: 3470945
• 负责人: ALAN M MICHELSON
• 金额: $ 11.55万
• 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/3470945
• 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; von Willebrand factor

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.

血小板粘附于受损的血管壁受损 von Willebrand因子（VWF）与血小板膜的结合 糖蛋白IB（GPIB）。 这项研究建议是对 生物化学，细胞生理和临床意义 VWF的GPIB受体。 该研究计划的具体目的是： 1）生物化学：表征VWF的绑定位点 GPIB。 我们最近证明了糖蛋白，一个 GPIB的蛋白水解片段包含VWF结合 地点。 我们现在建议表征 通过评估糖果蛋白的vWF来评估 在开发用于测试的测定中纯化的糖蛋白 糖蛋白/VWF结合。 2）细胞生理学：检验GPIB受体的假设 因为VWF是从血小板的内部处理到 血小板表面并因此进入血浆。 新方法 已经开发了利用单克隆抗体的 量化VWF的GPIB受体：a）血小板内部 （酶联免疫吸附测定法（ELISA） Triton X-114溶解的血小板的水相），b） 血小板表面（荧光激活的细胞分选 （FACS））和C）在等离子体（ELISA）中。 这些变化 洗涤后，将确定受体池 血小板和血小板浓缩物的存储。 3）临床意义：研究GPIB缺陷 继承的血小板疾病。 i）Wiskott-Aldrich综合征 （WAS）：通过FACS的初步研究表明 患者有两个亚群 血小板：一个GPIB阳性和另一个GPIB阴性。 我们现在建议表征GPIB缺陷在 患者和携带者。 ii）伯纳德 - 苏利尔综合症 （BSS）：已知BSS血小板缺乏表面GPIB VWF的受体。 为了澄清基本缺陷 在BSS中，该受体的内部和血浆库 将进行分析。 这些实验的结果可能会提供更好的 了解血小板粘附的病理生理学 受损的船墙。 临床适用的知识可能 从该研究计划中获得的包括：变化 储存过程中血小板浓缩物的粘合特性； 用于诊断WAS载体的甲级学；和新见解 鉴于可能的 VWF在这种疾病中的作用。