DESIGN OF MULTIMERIC INTERLEUKIN-2 RECEPTOR ECTODOMAINS

描述：白细胞介素-2是一种螺旋细胞因子， 在治疗某些恶性肿瘤和感染性疾病中的临床应用 包括艾滋病毒感染在内的疾病。 白细胞介素-2受体（IL-2 R）是一种 最复杂的受体系统 受体。 它可以以各种亲和力状态存在，这取决于 三个独立细胞表面的不同组合的参与 亚基：IL-2 R α、β和γ。 这些亚单位的功能是 两种特异性异二聚体（IL-2 R α β）和（IL-2 R β γ）以及一种 异源三聚体（IL-2 R α β γ）。 每一个细胞表面组件 有着独特的生理功能 正是这些合作性 在配体捕获和信号传递过程中， 来理解利用IL-2的治疗潜力。 这个项目 是第一个提出并实施使用螺旋线圈识别的人 用于复杂受体的溶液组装的序列（Leu Zippers） 系统. 在项目初期， 建立了方法，并开发了表达和 可溶性IL-2 R卷曲螺旋复合物的表征。 卷曲螺旋 介导的溶液组装产生异聚IL-2 R复合物， 配体以类似于它们的细胞表面对应物的方式。 这些 复合物已经证明可用于IL-2结构/功能分析。 本提案要求继续开展这项工作，目标是 稳定的解决方案组装和所有三个完整的表征， 功能性异聚体IL-2 R复合物。 本项目的具体目标 是：1. 表达、分离和鉴定两种功能性IL-2 受体异二聚体（IL-2 R α β假高亲和力和IL-2 R β假高亲和力） γ中间亲和受体）作为稳定的卷曲螺旋复合物。 2. 表达、分离和鉴定假定的IL-2受体 异源三聚体高亲和力受体（IL-2 R α β γ）作为稳定的 卷曲螺旋复合体 3. 为了确定平衡和动力学配体 每个受体复合物的结合特征。 4. 获得详细 这些复合物的结构-活性数据，通过共结晶它们与 IL-2，并确定其X射线结构的高分辨率。

DESCRIPTION: Interleukin-2 is a helical cytokine that has found wide spread clinical use in the treatment of some malignancies and for infectious diseases including HIV infection. The interleukin-2 receptor (IL-2R) is one of the most complex receptor systems of the large family of hematopoietin receptors. It may exist in a variety of affinity states depending upon the participation of different combinations of three separate cell surface subunits: IL-2Ralpha, beta and gamma. These subunits function in the form of two specific heterodimers (IL-2Ralpha beta) and (IL-2Rbeta gamma) and one heterotrimer (IL-2Ralpha beta gamma). Each of these cell surface assemblies performs a distinct physiologic function. It is the cooperativity of these subunits during ligand capture and signal transmission that provides the key to understanding exploiting the therapeutic potential of IL-2. This project was the first to propose and implement the use of coiled-coil recognition sequences (Leu Zippers) for the solution assembly of complex receptor systems. During the initial project period, the feasibility of this approach was established and methods were developed for the expression and characterization of soluble IL-2R coiled-coil complexes. Coiled-coil mediated solution assembly generated heteromeric IL-2R complexes that bound ligand in a fashion that resembled their cell surface counterparts. These complexes are already proving useful for IL-2 structure/function analysis. This proposal is a request for continuation of this work with the goals of stable solution assembly and complete characterization of all three of the functional heteromeric IL-2R complexes. The Specific Aims of this project are: 1. To express, isolate and characterize the two functional IL-2 receptor heterodimers (IL-2Ralpha beta pseudo high affinity and IL-2R beta gamma intermediate affinity receptors) as stable coiled-coil complexes. 2. To express, isolate and characterize the presumed IL-2 receptor heterotrimeric high affinity receptor (IL-2Ralpha beta gamma) as a stable coiled-coil complex. 3. To determine the equilibrium and kinetic ligand binding characteristics of each receptor complex. 4. To obtain detailed structure-activity data on these complexes by co-crystallizing them with IL-2 and determining their X-ray structures to high resolution.