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: 8053831
• 负责人: Charles G. Glabe
• 金额: $ 28.75万
• 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/8053831
• 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; Health; 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; polyclonal antibody; prevent; programs; 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）：该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寡聚体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物在患病大脑中积聚，目前的证据表明可溶性寡聚形式的 Ass 可能在发病机制中发挥主要作用。最近的结果表明，构象依赖性单克隆抗体可以区分不同类型的可溶性 Ass 寡聚物。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。我们最近制备了两种额外的构象依赖性抗血清，它们识别与淀粉样蛋白原纤维和由许多不同类型的淀粉样蛋白形成的孔状环形原原纤维相关的通用表位（参见下面的初步数据）。这些抗体与抗寡聚体抗体 A11 互补，并识别原纤维和环状初原纤维聚集体特异的表位。我们假设 Ass 这些构象不同的组装状态与 AD 发病机制有不同的相关性。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，例如观察到沉积的总淀粉样蛋白与疾病相关性较差，并且有些人具有大量淀粉样蛋白并且认知正常，而其他大脑样本几乎没有可观察到的淀粉样蛋白。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寡聚体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，因为它们仅识别特定的错误折叠状态，并且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蛋白寡聚体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？不同淀粉样蛋白构象状态的病理意义是什么？这些问题的答案应有助于深入了解淀粉样蛋白寡聚物构象多样性的范围以及区分寡聚物不同构象的单克隆抗体试剂。这可能为低聚物的分类提供更合理的结构基础，并深入了解不同实验室报告的低聚物制剂的变异性。确定与淀粉样蛋白寡聚物结合的单克隆 Fab 的 3 维结构可以为淀粉样蛋白寡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寡聚物形成或防止其与细胞靶点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有助于澄清低聚物是否是形成更高级结构（如原纤维）的中间体，或者它们是否代表稳定的替代最终产物。这一目标还可以提供专门抑制淀粉样蛋白寡聚体形成的小分子先导化合物，用于治疗开发。哪些类型的淀粉样蛋白寡聚体与人类和转基因小鼠大脑的发病机制更密切相关的特征可能有助于确定治疗开发的靶点。 PHS 398/2590 (Rev. 04/06) 页面延续格式页面 公共健康相关性：淀粉样蛋白聚集体被认为在神经退行性疾病（如阿尔茨海默病、帕金森病、亨廷顿病和朊病毒病）的发展中发挥着核心作用。该提案的目标是确定存在多少种不同类型的淀粉样蛋白聚集体，并确定淀粉样蛋白聚集体的精确 3 维结构。该提案还将检查这些聚集体中哪些对神经元毒性更大，并且与疾病关系最密切。另一个好处是，该提案可能会产生专门针对这些淀粉样蛋白聚集体进行治疗开发的单克隆抗体和药物。