Structure and conformational diversity of amyloid oligomers

淀粉样蛋白寡聚物的结构和构象多样性

• 批准号: 7897965
• 负责人: Charles G. Glabe
• 金额: $ 27.92万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-04-01 至 2015-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7897965
• 关键词: Address; Affinity; Alzheimer' s Disease; Amino Acid Sequence; Amyloid; Amyloid Fibrils; Amyloid Proteins; Antibodies; Antibody Specificity; Asses; Binding; Brain; Brain Diseases; Cells; Classification; Cognitive; Conflict (Psychology); Data; Deposition; Development; Disease; Epitopes; Face; Generic Drugs; Goals; Heterogeneity; Higher Order Chromatin Structure; Human; Huntington Disease; Immune Sera; Impaired cognition; In Vitro; Laboratories; Lead; Ligands; Molecular Conformation; Monitor; Monoclonal Antibodies; Mutation; Neurodegenerative Disorders; Neurons; Parkinson Disease; Pathogenesis; Pathology; Pathway interactions; Peptides; Pharmaceutical Preparations; Play; Preparation; Presenile Alzheimer Dementia; Principal Investigator; Prion Diseases; Protein Precursors; Proteins; Publishing; Rattus; Reagent; Reporting; Research Project Grants; Role; Running; Sampling; Seeds; Side; Specificity; Structure; Testing; Toxic effect; Transgenic Mice; Variant; Vertebral column; aggregation pathway; amyloid structure; base; cellular targeting; conformer; insight; monomer; prevent; programs; public health relevance; small molecule; synthetic peptide; therapeutic development; therapeutic target; three dimensional structure

DESCRIPTION (provided by applicant): The goal of this research project is to explore the structural heterogeneity of amyloid aggregates and the relationships of this conformational variation to the toxicity or pathogenic activities of amyloid oligomers. Several distinct types of amyloid deposits accumulate in disease brain and current evidence suggests that soluble, oligomeric forms of Ass may play primary role in pathogenesis. Recent results indicate that conformation-dependent monoclonal antibodies can distinguish between different types soluble Ass oligomers. These antibodies also distinguish other conformations of Ass, including monomers, fibrils and natively-folded APP. We have recently prepared two additional conformation-dependent antisera that recognize generic epitopes associated with amyloid fibrils and pore-like annular protofibrils that are formed from many different types of amyloids (see Preliminary Data, below). These antibodies are complementary to the anti-oligomer antibody, A11 and recognize epitopes that are specific to fibrils and annular protofibril aggregates. We hypothesize that these conformationally distinct assembly states of Ass are differentially associated with AD pathogenesis. We anticipate that these results will help clarify some apparent inconsistencies and conflicting data, such as the observations that the total Ass amyloid deposited correlates poorly with disease and some people have large amounts of amyloid and are cognitive normal, while other brain samples that have little observable amyloid deposits are associated with cognitive dysfunction. We hypothesize that the distinct types of soluble oligomeric or annular protofibril forms of Ass have distinct toxicities. Conformation-dependent antibodies hold the potential of identifying and distinguishing specific assembly states because they only recognize a specific misfolded state and do not react with the natively folded precursor protein. The specific aims of this project will address the following questions: What is the conformational diversity of amyloid aggregates? What is the structural basis of conformation dependent antibody specificity and amyloid oligomer structural? What are the relationships between different conformational states of amyloids? What is the pathological significance of the different amyloid conformational states? The answers to these questions should provide insight into the range of amyloid oligomer conformational diversity and monoclonal antibody reagents that distinguish different conformations of oligomers. This may provide a more rational structural basis for the classification of oligomers and provide insight into the variability in oligomer preparations reported by different laboratories. Determining the 3 dimensional structure of the monoclonal Fabs bound to amyloid oligomers may provide unprecedented insight into the structure of amyloid oligomers and the mechanism of specific antibody recognition that may be useful for development of immunological therapeutics that target oligomer formation or prevent their interaction with cellular targets. The identification of small molecules that specifically inhibit the formation of different types of oligomers should help to clarify whether the oligomers are intermediates in the formation of higher order structures, like fibrils or whether they represent stable alternative end products. This aim may also provide small molecule lead compounds that specifically inhibit amyloid oligomer formation for therapeutic development. The characterization of which types of amyloid oligomers are more closely related to pathogenesis in human and transgenic mouse brain may help to identify targets for therapeutic development. PHS 398/2590 (Rev. 04/06) Page Continuation Format Page PUBLIC HEALTH RELEVANCE: Amyloid aggregates are believed to play a central role in the development of neurodegenerative diseases, like Alzheimer, Parkinson, Huntington and prion diseases. The goal of this proposal is to determine how many different types of amyloid aggregates exist and to determine the precise 3 dimensional structure of the amyloid aggregates. The proposal will also examine which of these aggregates is more toxic to neurons and most closely related to disease. An additional benefit is that this proposal may produce monoclonal antibodies and drugs that specifically target these amyloid aggregates for therapeutic development.

描述（由申请人提供）：本研究项目的目标是探索淀粉样蛋白聚集体的结构异质性以及这种构象变化与淀粉样蛋白低聚物的毒性或致病活性的关系。几种不同类型的淀粉样蛋白沉积在疾病大脑中积累，目前的证据表明可溶性低聚形式的淀粉样蛋白可能在发病机制中起主要作用。最近的研究表明，构象依赖的单克隆抗体可以区分不同类型的可溶性Ass低聚物。这些抗体还可以区分Ass的其他构象，包括单体、原纤维和天然折叠的APP。我们最近制备了另外两种构象依赖的抗血清，它们可以识别与淀粉样原纤维和孔样环状原纤维相关的通用表位，这些原纤维是由许多不同类型的淀粉样蛋白形成的（见下面的初步数据）。这些抗体与抗低聚物抗体A11互补，并识别原纤维和环状原纤维聚集物特异性的表位。我们假设这些构象上不同的Ass组装状态与AD的发病机制有不同的关联。我们预计这些结果将有助于澄清一些明显的不一致和相互矛盾的数据，例如观察到总的淀粉样蛋白沉积与疾病的相关性很差，一些人有大量的淀粉样蛋白并且认知正常，而其他大脑样本中几乎没有可观察到的淀粉样蛋白沉积与认知功能障碍有关。我们假设不同类型的可溶性低聚物或环状原纤维形式的Ass具有不同的毒性。构象依赖性抗体具有识别和区分特定组装状态的潜力，因为它们只识别特定的错误折叠状态，而不与天然折叠的前体蛋白发生反应。该项目的具体目标将解决以下问题：淀粉样蛋白聚集体的构象多样性是什么？构象依赖性抗体特异性和淀粉样低聚物结构的结构基础是什么？淀粉样蛋白的不同构象状态之间有什么关系？淀粉样蛋白不同构象状态的病理意义是什么？这些问题的答案应该提供洞察淀粉样蛋白低聚物构象多样性和单克隆抗体试剂区分不同的低聚物构象的范围。这可能为低聚物的分类提供更合理的结构基础，并为不同实验室报道的低聚物制剂的可变性提供见解。确定与淀粉样蛋白低聚物结合的单克隆fab的三维结构可能为淀粉样蛋白低聚物的结构和特异性抗体识别机制提供前所未有的见解，这可能有助于开发针对低聚物形成或阻止其与细胞靶标相互作用的免疫疗法。鉴定特异性抑制不同类型低聚物形成的小分子应该有助于澄清低聚物是形成高阶结构（如原纤维）的中间产物，还是代表稳定的替代最终产物。这一目标也可能为治疗开发提供特异性抑制淀粉样蛋白低聚物形成的小分子先导化合物。确定哪些类型的淀粉样蛋白低聚物与人类和转基因小鼠大脑的发病机制更密切相关，可能有助于确定治疗开发的靶点。小灵通398/2590 （Rev. 04/06）页延续格式页