C3d/EBV Receptor Ligand Binding Sites

C3d/EBV 受体配体结合位点

• 批准号: 7072770
• 负责人: Vernon Michael Holers
• 金额: $ 24.61万
• 依托单位: UNIVERSITY OF COLORADO DENVER
• 依托单位国家: 美国
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7072770
• 关键词: B lymphocyte; Epstein Barr virus; X ray crystallography; binding sites; complement; complement receptor; gene mutation; genetically modified animals; laboratory mouse; nuclear magnetic resonance spectroscopy; protein structure; receptor binding; virus protein

DESCRIPTION (provided by applicant): Human complement receptor type 2 (CR2/CD21) is an ~145 Kd Type I transmembrane protein that serves as a receptor for three classes of ligands. These include C3 cleavage fragments (C3d, C3dg and iC3b), Epstein-Barr virus gp350/220 and CD23. Each of these ligands interacts with the amino-terminal region of the receptor within 2 of 16 repetitive elements that have been designated short consensus repeats (SCRs). SCR-containing proteins that interact with complement C3 and/or C4 are part of a family called the Regulators of Complement Activation (RCA). While the biologic relevance of these proteins is well established, important structure-function characteristics of SCR-containing proteins are poorly understood at the molecular level. We are studying CR2 as a model for receptor-ligand interactions in this family, initially focusing on the amino terminal domain that is designated herein the SCR1-2 domain and which interacts with each of the ligands described above. Preliminary studies using solution as well as x-ray crystallographic techniques have identified several protein-protein interfaces that are likely key to receptor interactions of CR2 with the C3d ligand as well as strongly suggested a model in which the non-ligand-bound free and ligand-bound structures of the SCR1-2 domain differ in their conformation. In addition, recent data have shown that SCRs of CR2 outside of the SCR1-2 domain influence binding with C3d. We now propose to extend these studies by pursuing the following specific aims:Specific Aim #1: Determine the solution phase structure of the CR2 SCR1-2 domain in order to establish the physical relationship between the non-ligand-bound and C3d-ligand-bound receptor states.Specific Aim #2: Establish the relative roles of the three unique protein-protein interfaces apparent in the CR2 SCR1-2:C3d co-crystal structure in C3d ligand binding, signal transduction and the enhancement of in vivo immune responses.Specific Aim #3: Determine the relationship between the C3d, gp350/200 and CD23 ligand binding sites within the CR2 SCR1-2 domain.Specific Aim #4: Establish the solution structure of the CR2 SCR1-15/16 extracellular domain and determine the physical basis for the altered CR2-C3d ligand-receptor binding kinetics when comparing this full length receptor with the CR2 SCR1-2 domain.

描述（由申请人提供）：人补体受体2型（CR2/CD 21）是一种~145 Kd的I型跨膜蛋白，作为三类配体的受体。这些包括C3切割片段（C3 d、C3 dg和iC 3b）、爱泼斯坦-巴尔病毒gp 350/220和CD 23。这些配体中的每一个与16个重复元件中的2个内的受体的氨基末端区域相互作用，所述重复元件已被指定为短共有重复序列（SCR）。与补体C3和/或C4相互作用的含SCR蛋白是称为补体激活调节因子（RCA）的家族的一部分。虽然这些蛋白质的生物学相关性已经很好地建立，但在分子水平上对含SCR蛋白质的重要结构-功能特征知之甚少。我们正在研究CR2作为该家族中受体-配体相互作用的模型，最初集中在氨基末端结构域，其在本文中被指定为SCR 1 -2结构域，并且其与上述每个配体相互作用。使用溶液以及X射线晶体学技术的初步研究已经确定了几种蛋白质-蛋白质界面，这些界面可能是CR2与C3 d配体的受体相互作用的关键，并且强烈建议了一种模型，其中SCR 1 -2结构域的非配体结合的游离和配体结合的结构在其构象上不同。此外，最近的数据表明，SCR 1 -2结构域之外的CR2的SCR影响与C3 d的结合。我们现在建议通过追求以下具体目标来扩展这些研究：具体目标#1：确定CR2 SCR 1 -2结构域的溶液相结构，以建立非配体结合和C3 d配体结合受体状态之间的物理关系。具体目标#2：建立CR2 SCR 1 -2中明显的三种独特蛋白质-蛋白质界面的相对作用：C3 d共晶体结构在C3 d配体结合、信号转导和增强体内免疫应答中的作用。具体目标#3：确定CR2 SCR 1 -2结构域内C3 d、gp 350/200和CD 23配体结合位点之间的关系。具体目标#4：建立CR2 SCR 1 -15/16胞外结构域的溶液结构，并在比较该全长受体与CR2 SCR 1 -2结构域时确定CR2-C3 d配体-受体结合动力学改变的物理基础。

项目成果

CD23 interacts with a new functional extracytoplasmic domain involving N-linked oligosaccharides on CD21.

CD23 与 CD21 上涉及 N 连接寡糖的新功能胞质外结构域相互作用。

• 发表时间: 1994
• 期刊: Journal of immunology (Baltimore, Md. : 1950)
• 作者: Aubry,JP;Pochon,S;Gauchat,JF;Nueda-Marin,A;Holers,VM;Graber,P;Siegfried,C;Bonnefoy,JY
• 通讯作者: Bonnefoy,JY

Extended flexible linker structures in the complement chimaeric conjugate CR2-Ig by scattering, analytical ultracentrifugation and constrained modelling: implications for function and therapy.

通过散射、分析超速离心和约束建模扩展补体嵌合缀合物 CR2-Ig 中的柔性接头结构：对功能和治疗的影响。

• DOI: 10.1016/j.jmb.2005.11.050
• 发表时间: 2006
• 期刊: Journal of molecular biology.
• 作者: Gilbert,HannahE;Aslam,Mohammed;Guthridge,JoelM;Holers,VMichael;Perkins,StephenJ
• 通讯作者: Perkins,StephenJ