Structural Biology of Amyloid Disease

淀粉样蛋白疾病的结构生物学

• 批准号: 8066966
• 负责人: DAVID EISENBERG
• 金额: $ 38.87万
• 依托单位: UNIVERSITY OF CALIFORNIA LOS ANGELES
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8066966
• 关键词: Alzheimer' s Disease; Amino Acid Sequence; Amino Acids; Amyloid; Amyloid Fibrils; Amyloid Proteins; Amyloidosis; Architecture; Behavior; Collaborations; Computational Biology; Crystallography; Diagnostic; Disease; Face; Foundations; Glutamine; Grant; Huntington Disease; Learning; Length; Literature; Methods; Mutate; Neurodegenerative Disorders; Non-Insulin-Dependent Diabetes Mellitus; Paper; Parents; Parkinson Disease; Pattern; Peptide Sequence Determination; Prion Diseases; Prions; Procedures; Proteins; Research; Resolution; Rest; Roentgen Rays; Screening procedure; Seeds; Solid; Structural Protein; Structure; Therapeutic; United States National Institutes of Health; Vertebral column; Work; alpha synuclein; amyloid structure; base; beta pleated sheet; novel; programs; protein aggregation; structural biology; sup35; synuclein; tau Proteins; yeast prion

DESCRIPTION (provided by applicant): The aggregation of proteins in Alzheimer's, Parkinson's, prion diseases, Huntington's, and other amyloid-like diseases will be illuminated by methods of structural and computational biology. Background research by microcrystallography has shown that the fundamental structural unit of amyloid-like fibrils is a set of beta sheets, in which the amino acid sidechains of neighboring sheets intermesh, in what is termed a steric zipper. The steric zipper interface between the faces of the sheets is completely dry. The protein segments that form the sheets are as short as 4-8 residues in length, stacking either in parallel or antiparallel to grow a fibril, but the segments can be longer and some proteins contain several such segments. To learn the structures of amyloid fibrils from disease-associated proteins, the same methods of microcrystallography will be applied to microcrystals grown from short segments of the A? and Tau proteins of Alzheimer's disease, from the PrP protein of the prion diseases, from ?-synuclein of Parkinson's disease, and from proteins involved in ALS and diabetes type 2. To learn what happens during fibril formation to the rest of the protein, structural studies will also be conducted on larger segments and entire fibril-forming proteins, using novel methods of crystal screening and microcrystallography. Preliminary work shows that computational energetics can identify which segments from proteins are those that are fibril-forming and can be grown into microcrystals, suitable for structural determination. This procedure is based on the 3D Profile method for finding sequences that fit a given fold (in this case the steric zipper), using energy functions. The procedure will be extended and applied to amyloids. Once a segment has been discovered which forms fibrils, and its structure has been determined by crystallography as belonging to the steric-zipper type of architecture, the connection between the segment and fibrils of the full protein can be assessed by whether the segment can seed the full protein into fibrils. Further proof of the connection of the segment and fibrils of the full protein can be obtained by mutating residues in the protein that correspond to residues of the segment, and looking for diminished fibrillization. These structures, derived by novel methods of microcrystallography, are the first high-resolution (up to 0.85 A resolution), fully refined atomic structures for the amyloid state. They show that there are at least 4 basic patterns for the steric zipper spines of amyloid fibrils, and perhaps up to 7 such patterns. These structures offer a solid foundation on which to devise diagnostics and therapeutics for these devastating neurodegenerative diseases.

描述（由申请人提供）：阿尔茨海默病、帕金森病、朊病毒病、亨廷顿病和其他淀粉样疾病中的蛋白质聚集将通过结构和计算生物学的方法来阐明。微晶体学研究表明，淀粉样原纤维的基本结构单元是一组β片，其中相邻片的氨基酸侧链相互啮合，形成所谓的立体拉链。面与面之间的立体拉链界面是完全干燥的。形成薄片的蛋白质片段长度只有4-8个残基，以平行或反平行的方式堆叠形成原纤维，但这些片段可以更长，有些蛋白质包含几个这样的片段。为了从疾病相关蛋白中了解淀粉样蛋白原纤维的结构，同样的微晶体学方法将应用于从A？阿尔茨海默病的Tau蛋白，朊病毒疾病的PrP蛋白？-突触核蛋白，以及与肌萎缩侧索硬化症和2型糖尿病有关的蛋白质。为了了解蛋白质其余部分的原纤维形成过程中发生了什么，结构研究也将在更大的片段和整个原纤维形成蛋白质上进行，使用新的晶体筛选和微晶体学方法。初步的工作表明，计算能量学可以从蛋白质中识别出哪些片段是纤维形成的，可以生长成微晶体，适合于结构测定。该过程基于3D Profile方法，使用能量函数寻找适合给定褶皱（在本例中为立体拉链）的序列。该程序将扩展并应用于淀粉样蛋白。一旦发现了形成原纤维的片段，并且通过晶体学确定其结构属于立体拉链型结构，则可以通过片段是否可以将完整蛋白质植入原纤维来评估该片段与完整蛋白质原纤维之间的连接。通过突变蛋白质中与片段残基相对应的残基，并寻找减少的纤化，可以进一步证明片段和全蛋白原纤维的连接。这些结构是通过微晶体学的新方法得到的，是第一个高分辨率（高达0.85 A分辨率）的淀粉样蛋白状态的完全精细的原子结构。他们表明，淀粉样蛋白原纤维的立体拉链棘至少有4种基本模式，可能多达7种。这些结构为这些毁灭性的神经退行性疾病的诊断和治疗提供了坚实的基础。