INFLUENCE OF APOLIPOPROTEIN E STRUCTURE ON FUNCTION

载脂蛋白 E 结构对功能的影响

• 批准号: 6564894
• 负责人: KARL WEISGRABER
• 金额: $ 23.92万
• 依托单位: J. DAVID GLADSTONE INSTITUTES
• 依托单位国家: 美国
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-02-01 至 2003-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6564894
• 关键词: X ray crystallography; apolipoprotein E; blood lipoprotein metabolism; cholesterol; conformation; human subject; laboratory rabbit; low density lipoprotein; low density lipoprotein receptor; phlebotomy; protein isoforms; protein protein interaction; protein structure; protein structure function; receptor binding; receptor expression; site directed mutagenesis; surface property

Project 1: Influence of Apolipoprotein E Structure on Function: Apolipoprotein (apo-)E is a major mediator of lipoprotein metabolism via its interaction with members of the low density lipoprotein (LDL) receptor family. Polymorphic differences in the structure of apo-E have a major impact on apo-E-mediated lipoprotein metabolism. In addition, apo-E4, a structural isoform, is a major risk factor for Alzheimer's disease and other neurodegenerative disorders. Therefore, it is critically important to understand the influence of apo-E structure on its functions. The overall objective of this proposal focuses on the structure/function relationships of apo-E-related to lipoprotein metabolism, using x-ray crystallography as the primary structural tool. Previously, we introduced the concept of domain interaction-that the two structural domains of apo-E influence each other's functional properties-and determined how this interaction directs apo-E4's binding preference for very low density lipoproteins. In this proposal, we will extend our studies on domain interaction to elucidate the increased receptor-binding activity of apo- E4, to explore other aspects of domain interaction in both in vitro and in vivo model systems, and to gain a better understanding of the structure of lipid-bound apo-E. In addition, we will determine the structure of the LDL receptor and define the structure of the LDL receptor and define the molecular interface of the receptor and bound apo-E. We propose two specific aims to achieve these objectives. In Aim 1, we will determine the x-ray structures of the LDL receptor and several physiologically relevant forms of apo-E. In addition to lipid-free forms, the structures of lipid- associated or detergent-treated apo-E will be determined to define the structural change that occurs when apo-E goes from a lipid-free, receptor- inactive state to a lipid-associated, receptor-active state. In Aim 2, we will study the effect of domain interaction on receptor-binding function and test the hypothesis that a second distinct group of arginine residues within the hinge region of apo-E contributes to receptor-binding activity. The proposed studies will lead to new insights into how the structural differences in apo-E contribute to isoform-specific effects in lipoprotein metabolism, heart disease, and Alzheimer's disease.

项目1：载脂蛋白E结构对功能的影响： 载脂蛋白（Apo-）E是脂蛋白代谢的主要介体 它与低密度脂蛋白（LDL）受体成员的相互作用 家庭。 Apo-E结构的多态性差异具有主要 对APO-E介导的脂蛋白代谢的影响。此外，apo-e4，a 结构同工型，是阿尔茨海默氏病和 其他神经退行性疾病。因此，至关重要 了解Apo-E结构对其功能的影响。这 该提案的总体目的集中于结构/功能 使用X射线 晶体学作为主要结构工具。以前，我们介绍了 域相互作用的概念 - apo-e的两个结构域 影响彼此的功能属性，并确定如何 相互作用指导Apo-E4的结合偏好对于非常低的密度 脂蛋白。在此提案中，我们将扩展有关领域的研究 相互作用以阐明apo-的受体结合活性增加 e4，探索体外和中域相互作用的其他方面 体内模型系统，并更好地了解 脂质结合的apo-e。此外，我们将确定LDL的结构 受体并定义LDL受体的结构，并定义 受体和结合apo-e的分子界面。我们提出了两个 实现这些目标的具体目的。在AIM 1中，我们将确定 LDL受体的X射线结构和几种与生理相关的结构 apo-e的形式。除了无脂质形式外，脂质的结构 将确定相关或洗涤剂处理的APO-E定义 当apo-e从无脂质的受体 - 非活性状态至脂质相关的受体活跃状态。在AIM 2中，我们 将研究域相互作用对受体结合功能的影响 并检验第二个不同的精氨酸残基的假设 在APO-E的铰链区域内有助于受体结合活性。 拟议的研究将导致对结构如何的新见解 APO-E的差异有助于脂蛋白中的同工型特异性作用 代谢，心脏病和阿尔茨海默氏病。