X-ray Studies of SOD in Amyotrophic Lateral Sclerosis

肌萎缩侧索硬化症中 SOD 的 X 射线研究

基本信息

批准号：
7613337
负责人：
Peter JOHN HART
金额：
$ 31.9万
依托单位：
UNIVERSITY OF TEXAS HLTH SCIENCE CENTER
依托单位国家：
美国
项目类别：
财政年份：
2000
资助国家：
美国
起止时间：
2000-05-05 至 2011-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7613337
关键词：
3-Dimensional Alzheimer&apos s Disease Amino Acid Substitution Amyloid Amyotrophic Lateral Sclerosis Animals Applications Grants Binding Binding Sites Biological Assay Brain Categories Cell Aggregation Cells Cellular Membrane Cessation of life Collaborations Congo Red Copper DNA Sequence Rearrangement Degenerative Disorder Degradation Pathway Digestion Disease Disulfides Elements Embryo Engineering Environment Enzymes Erythrocytes Familial Amyotrophic Lateral Sclerosis Fiber Filament Florida Future Goals Higher Order Chromatin Structure Human Hydrogen Peroxide Hydrophobicity In Vitro Indium Inherited Institutes Ions Laboratories Lesion Life Link Location Mammalian Cell Mediating Metalloproteins Metals Methods Mitochondria Molecular Molecular Conformation Molecular Probes Molecular Weight Motor Neuron Disease Motor Neurons Mutation Neurodegenerative Disorders Neurons Nucleosome Core Particle Oxygen Paralysed Parkinson Disease Pathogenicity Pathway interactions Patients Play Principal Investigator Process Progress Reports Property Proteins Research Personnel Research Project Grants Roentgen Rays Role SOD1 gene Scaffolding Protein Series Site Solutions Spatial Distribution Spinal Spinal Cord Structure Study Section Superoxides Surface Surface Plasmon Resonance System Testing Therapeutic Agents Tissues Toxic effect Transgenic Mice Tube Ubiquitin United States National Institutes of Health Universities Variant X ray diffraction analysis X-Ray Diffraction Yeasts Zinc absorption analytical ultracentrifugation base copper zinc superoxide dismutase cytotoxic design dimer disulfide bond falls gain of function in vivo inhibitor/antagonist interest kidney cell light scattering member monomer motor neuron degeneration mouse model multicatalytic endopeptidase complex mutant neurotoxic novel professor programs protein aggregate protein degradation protein misfolding protein oligomer research study three dimensional structure tool

项目摘要

DESCRIPTION (provided by applicant): Human copper-zinc superoxide dismutase (SOD1) is a 32 kDa homodimeric metalloprotein that catalyzes the conversion of superoxide radical into molecular oxygen and hydrogen peroxide. The enzyme is particularly abundant in red blood cells and spinal tissue. Approximately 114 different single site mutations in human SOD1 have been linked to an inherited form of amyotrophic lateral sclerosis (ALS, Lou Gehrig's disease, motor neuron disease). Both the inherited (FALS) and sporadic (SALS) forms of the disease are characterized by progressive paralysis resulting from motor neuron degeneration and death. It is now established that SOD1-linked FALS results from the gain of a cytotoxic property and not a loss of enzymatic function. Evidence is accumulating that the toxic property comes from the ability of the mutant SOD1 proteins to assemble into higher order structures (soluble oligomers and insoluble aggregates) that somehow interfere with the neuronal cellular machinery. Using the well established tools of single crystal X-ray diffraction, we recently observed that six different metal-deficient FALS mutant SOD1 proteins can form "amyloid-like" fibers that are somewhat reminiscent of the types of fibers seen in other neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. The pathogenic SOD1 proteins are able to self- associate but the normal, unmutated SOD1 proteins cannot. The experiments outlined in this continuing project are designed to probe pathogenic SOD1 structure and to help answer the following questions: 1) What are the structural consequences of the FALS mutations and how do these amino acid substitutions render the molecule toxic? 2) Does the loss of metal ions play a role in FALS SOD1 pathogenicity? 3) How does the presence or absence of the intrasubunit disulfide bond influence the structural and biophysical properties of pathogenic SOD1? 4) Is the mode of self-association we observe in X-ray studies the basis for how the pathogenic SOD1 proteins aggregate in living cells? 5) What are the structural elements of SOD1 proteins that are recognized by the 20 S proteasome so that they may be degraded? 6) Could soluble oligomers (protofibrils) and/or insoluble amyloids of pathogenic SOD1 act as proteasomal inhibitors? Answers to questions such as these are required for a molecular understanding of SOD1 linked FALS and for the design of therapeutic agents aimed inhibiting the aggregation process.

描述（由申请人提供）：人类铜 - 锌超氧化物歧化酶（SOD1）是32 kDa同型二聚体金属蛋白，可促进超氧化物自由基转化为分子氧和过氧化氢。该酶在红细胞和脊柱组织中特别丰富。人类SOD1中约有114个不同的单位突变已与植物营养性侧索硬化症的遗传形式有关（ALS，Lou Gehrig病，运动神经元疾病）。疾病的遗传（fals）和零星（sals）形式的特征是运动神经元变性和死亡引起的进行性瘫痪。现在已经确定，SOD1连接的FAL是由于细胞毒性特性的增益而不是酶促功能的损失而产生的。有证据表明，有毒特性来自突变的SOD1蛋白组装成高阶结构（可溶性低聚物和不溶性骨料）的能力，这些结构以某种方式干扰了神经元细胞机械。使用单晶X射线衍射的良好工具，我们最近观察到，六种不同的金属缺陷型fals突变体Sod1蛋白可以形成“淀粉样蛋白样”纤维，这些纤维有些让人联想到其他神经变性疾病（例如阿尔茨海默氏症和帕金森氏病。致病性SOD1蛋白能够自我缔合，但未直接的SOD1蛋白不能自我缔合。该持续项目中概述的实验旨在探测致病性SOD1结构并帮助回答以下问题：1）fals突变的结构后果是什么，这些氨基酸取代如何使分子有毒？ 2）金属离子的损失是否在fals Sod1致病性中起作用？ 3）亚基内二硫键的存在或不存在致病SOD1的结构和生物物理特性如何？ 4）我们在X射线研究中观察到的自我关联模式是活细胞中致病性SOD1蛋白如何聚集的基础吗？ 5）SOD1蛋白的结构元素是哪些由20 s蛋白酶体识别的，以便它们可能会降解？ 6）可溶性低聚物（原纤维）和/或致病性SOD1的不溶性淀粉样蛋白可以用作蛋白酶体抑制剂吗？对SOD1相关的伪造的分子理解以及旨在抑制聚集过程的治疗剂的设计，需要对此类问题的答案。