STRUCTURE - FUNCTION RELATIONSHIPS OF THE IGE RECEPTOR

IGE 受体的结构-功能关系

• 批准号: 3127826
• 负责人: Barbara A Baird
• 金额: $ 11.12万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1981
• 资助国家: 美国
• 起止时间: 1981-08-01 至 1987-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3127826
• 关键词: cell fusion; chemical structure function; fluorescent dye /probe; immunochemistry; immunoglobulin E; membrane activity; monoclonal antibody; tissue /cell culture

The work proposed is a continuation of analyses of the three-dimensional structure of the immunoglobulin E(IgE)-receptor complex, its interactions with other cellular components, and the mechanism by which it transmits a signal across the plasma membrane of mast cells and basophils to trigger degranulation in allergic responses. Structural mapping of distances between well-defined sites in IgE, the receptor, and the membrane surface will be continued using resonance energy transfer methods, and a new approach to this technique will be developed using fluorescently-labeld monoclonal antibodies specific for sites in the IgE-receptor complex. Functional effects of the monoclonals on cellular degranulation will be tested and correlated to their structural locations. Biochemical studies on the membrane -bound receptor will be aimed at extending previous information about the cytoplasmic exposure of the Beta and Gamma subunits by examining the susceptibility of membrane-bound receptor to limited proteolytic digestion. Other biochemical studies on the structure of the IgE-receptor complex will include an attempt to photoaffinity label a potential protein kinase site on the receptor and efforts to isolate and Fc fragment of rodent IgE that binds to the receptor. An understanding of the details of the interaction of IgE with the receptor should ultimately aid in the development of receptor-specific anti-allergic pharmaceuticals. Recent observations of large-scale clustering of receptors on the cell surface that is induced by small oligomers of IgE will be extended by making quantitative measurements with fluorescence photobleaching recovery and resonance energy transfer methods. These approaches should permit analysis of the kinetics of the clustering under conditions that are relevant to degranulation such that the temporal relationship between two processes may be assessed. Biochemical studies will be directed toward the identification of cellular components that interact with clustered receptors and thereby may be involved in the transmembrane signal. For these purposes chemical cross-linking and selective cytoskeletal depolymerigation methods will be used to isolate receptor-associated components from detergent-solubilized cells. These studies should contribute new insights to structural and functional chain-of-events between antigen bridging of IgE-receptor complexes on the cell surface and the degranulation signal.

所提出的工作是三维分析的延续 免疫球蛋白 E(IgE)-受体复合物的结构及其相互作用 与其他细胞成分，以及它传输的机制 信号穿过肥大细胞和嗜碱性粒细胞的质膜以触发 过敏反应中的脱颗粒。 距离的结构映射 IgE、受体和膜表面明确的位点之间 将继续使用共振能量转移方法，以及一种新的 该技术的方法将使用荧光标记来开发 对 IgE 受体复合物中的位点具有特异性的单克隆抗体。 单克隆抗体对细胞脱颗粒的功能影响将是 进行测试并与其结构位置相关。 生化研究 膜结合受体的作用将旨在延长先前的 有关 Beta 和 Gamma 亚基的细胞质暴露的信息 通过检查膜结合受体对有限的敏感性 蛋白水解消化。 其他有关结构的生化研究 IgE 受体复合物将包括尝试光亲和标记 受体上潜在的蛋白激酶位点以及分离 Fc 的努力 与受体结合的啮齿动物 IgE 片段。 的理解 IgE 与受体相互作用的细节最终应该会有所帮助 开发受体特异性抗过敏药物。 最近对细胞上大规模受体聚集的观察 由 IgE 小寡聚体诱导的表面将通过以下方式扩展 通过荧光光漂白恢复进行定量测量 和共振能量转移方法。 这些方法应该允许 分析在以下条件下的聚类动力学 与脱粒相关，使得两个之间的时间关系 可以评估流程。 生化研究将针对 识别与簇相互作用的细胞成分 受体，从而可能参与跨膜信号。 为了 这些目的化学交联和选择性细胞骨架 解聚方法将用于分离受体相关的 来自去污剂溶解的细胞的成分。 这些研究应该 为结构和功能事件链提供新的见解 细胞表面 IgE-受体复合物的抗原桥接之间 脱粒信号。