DESIGN OF MULTIMERIC INTERLEUKIN-2 RECEPTOR ECTODOMAINS

白介素2：白介素2受体的相互作用是 研究最深入的配体受体系统 造血/淋巴因子家族。最近的发现表明， 在许多方面，系统仍然是一个谜。不仅是生物化学的 信号转导机制未知，但在过去一年中 IL-2的长期三维结构已被证明是 不正确，并且已经确定了第三个细胞表面受体亚单位。 三个细胞表面亚单位(p55、p64和p75)的存在导致了这一点 在不断扩大的造血家族中独一无二的受体系统 感受器。关于每个亚单位如何相对于 配体的捕获、信号传递和内化是必不可少的 用于开发基于配体的IL-2激动剂和拮抗剂。我们 其他人已经证明了这些亚单位必须作为 异源二聚体存在于细胞表面。只有一个亚基(P55)是 能够与溶液中的配体以一种类似于 细胞表面结合。这个项目的长期目标是设计 定向多聚体中相关的可溶性IL-2受体胞外结构域 通过利用关于以下方面的丰富知识来实现解决方案 卷曲(Leu-Zipper)分子的特异性和稳定性 承认。 该项目的具体目标是： A.设计和表达结合每个受体的融合蛋白 具有卷曲线圈识别序列的胞外结构域 特别是在溶液中直接亚基相互作用。 B.用生物物理学表征受体亚单位的络合作用 方法：研究方法。 C.定量测定可溶性受体的配基结合特性 并将它们与等效的细胞表面结构进行比较。 D.优化可溶性络合物的设计，使其与配体结合 将极大地促进这种配体受体的表征 系统。此外，这些结果还将证明， 这种方法用于研究造血学的其他成员 受体家族。

The interleukin-2: Interleukin-2 receptor interaction has been one of the most intensely investigated ligand receptor system of the hematopoietic/lymphokine family. Recent findings demonstrate that is system remains an enigma in many respects. Not only is the biochemical mechanism of signal transduction unknown, but within the last year the longstanding 3 dimensional structure for IL-2 has been shown to be incorrect and a third cell surface receptor subunit has been identified. The presence of three cell surface subunits (p55, p64 and p75) makes this receptor system unique among the expanding family of hematopoietic receptors. The knowledge of how each subunit functions with respect to ligand capture, signal transmission and in internalization is essential for the development of ligand based IL-2 agonists and antagonists. We and others have demonstrated that these subunits must function as heterodimers on the cell surface. Only one of the subunits (p55) is capable of interacting with ligand in solution in a manner that resembles cell surface binding. The long term goal of this project is to engineer soluble IL-2 receptor ectodomains that associate in a directed multimeric fashion in solution by exploiting the wealth of knowledge concerning the specificity and stability of coiled - coil (Leu Zipper) molecular recognition. The Specific Aims of this project are: A. To engineer and express fusion proteins that combine each receptor ectodomain with coiled- coil recognition sequences designed to specifically direct subunit interaction in solution. B. To characterize receptor subunit complexation using biophysical methods. C. To quantitate the ligand binding properties of the soluble receptor complexes and compare them to the equivalent cell surface structures. D. To optimize the designs of the soluble complexes such that bind ligand will greatly facilitate the characterization of this ligand receptor system. In addition, these results will demonstrate the feasibility of this approach for the study of other members of the hematopoietic receptor family.