MYELIN PO GLYCOPROTEIN: STRUCTURE & ADHESIVE MECHANISMS

髓磷脂 PO 糖蛋白：结构

• 批准号: 6343914
• 负责人: DANIEL A KIRSCHNER
• 金额: $ 18.26万
• 依托单位: BOSTON COLLEGE
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-01-15 至 2003-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6343914
• 关键词: X ray crystallography; Xenopus; animal tissue; cell cell interaction; glycoprotein structure; low angle X ray diffraction analysis; membrane structure; molecular assembly /self assembly; myelin; myelin glycoprotein; protein protein interaction; protein structure function; recombinant proteins

DESCRIPTION (Applicant's abstract): The overall objective of this application is to define the molecular organization of myelin, the diverse adhesive mechanisms that stabilize its multilamellar sheath, and what defects in its organization and molecular constituents may lead to dysmyelination or demyelination such as occur in certain peripheral neuropathies and in multiple sclerosis. The approach is based on a correlation of results from X-ray crystallography and solution scattering, membrane diffraction, and electron microscopy. The specific aims, which are focused on the structure and role of the major transmembrane protein of peripheral nerve myelin (P0-glycoprotein) are: (1) to determine the three-dimensional structure of P0-glycoprotein for human and Xenopus. The proteins analyzed will include recombinant molecules having the native amino acid sequence, as well as those having specific sequence alterations known to occur in human peripheral neuropathies. These studies will inform about the atomic structure of P0 and about the crystal contacts or adhesion interfaces that may be responsible for the role of this protein in myelin formation and stability. (2) To characterize the protein-protein interactions between nearest-neighbor P0 molecules in a membrane mimetic environment using small-angle X-ray scattering. The membrane protein will be solubilized in aqueous solutions of detergents at very low concentration, and solution scattering will be undertaken using a synchrotron X-ray source. These studies will provide information about the interprotein molecular contacts that P0 molecules make in a milieu that more closely resembles its native environment (the lipid bilayer of the myelin membrane) than does a crystal. (3) To evaluate the membrane-membrane interactions in myelin of Xenopus peripheral nerves. Determining the pH- and ionic strength-dependence of membrane structure and packing in dissected peripheral nerves that have been incubated at different will provide strong constraints for testing hypotheses about the adhesion mechanisms of P0 at both the cytoplasmic and extracellular membrane appositions. This hierarchy of experimental objectives will allow the investigator to uniquely correlate structural data from the atomic to the molecular, to the membrane level, and thus contribute to an understanding of the structural biology of a membrane protein that figures significantly in both health and disease.

描述（申请人的摘要）： 该应用是为了定义髓磷脂的分子组织，多样 稳定其多层鞘的粘合机制，什么缺陷 在其组织和分子成分中可能导致障碍症或 脱髓鞘，例如在某些周围神经病中发生的 硬化。该方法基于X射线结果的相关性 晶体学和溶液散射，膜衍射和电子 显微镜。具体目的是专注于 外周神经髓磷脂（P0-糖蛋白）的主要跨膜蛋白 为：（1）确定P0-糖蛋白的三维结构 人和Xenopus。分析的蛋白质将包括重组分子 具有天然氨基酸序列，以及具有特定的氨基酸序列 已知发生在人周围神经病中已知的序列改变。这些 研究将告知P0和晶体的原子结构 接触或粘附接口可能是负责此作用的 髓磷脂形成和稳定性中的蛋白质。 （2）表征 蛋白质蛋白质相互作用在A中最近邻邻P0分子之间 使用小角度X射线散射的膜模拟环境。膜 蛋白质将在非常低的洗涤剂水溶液中溶解 浓度和溶液散射将使用同步加速器进行 X射线源。这些研究将提供有关解释蛋白的信息 P0分子在环境中产生的分子接触更接近 类似于其本地环境（髓鞘膜的脂质双层） 比晶体。 （3）评估膜膜相互作用 异爪蟾周围神经的髓磷脂。确定pH和离子 膜结构的强度依赖性和在解剖外周中填充的强度 在不同的不同的神经会提供强大的限制 用于测试有关P0的粘附机制的假设 细胞质和细胞外膜上的作用。这个层次结构 实验目标将允许研究者唯一关联 从原子到分子到膜水平的结构数据， 因此有助于理解膜的结构生物学 在健康和疾病中显着的蛋白质。