Design of antibody fragments specific for amyloidogenic aggregates

淀粉样蛋白形成聚集物特异性抗体片段的设计

• 批准号: 8631424
• 负责人: Peter M Tessier
• 金额: $ 27.23万
• 依托单位: RENSSELAER POLYTECHNIC INSTITUTE
• 依托单位国家: 美国
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-04-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8631424
• 关键词: Affinity; Alzheimer' s Disease; Amyloid; Amyloid Fibrils; Amyloid beta-Protein; Antibodies; Antigen Targeting; Antigens; Area; Binding; Complementarity Determining Regions; Development; Diagnostic; Disease; Entropy; Goals; Health; Human; Huntington Disease; Immunization; Immunoglobulin Fragments; Lead; Length; Linear Sequence Epitopes; Link; Mediating; Non-Insulin-Dependent Diabetes Mellitus; Outcome; Parkinson Disease; Peptide Fragments; Peptides; Prion Diseases; Proteins; Relative (related person); Research; Series; Specificity; Testing; Therapeutic; Work; abeta accumulation; alpha synuclein; amyloid formation; antigen binding; base; complementarity-determining region 3; conformer; design; monomer; novel; particle; polypeptide; prevent; protein aggregate

DESCRIPTION (provided by applicant): A grand challenge in biomolecular research is to rationally design antibodies that bind to target antigens with high affinity and specificity. The goal of this proposal is to elucidate principles for designing the complementarity-determining regions (CDRs) of antibody fragments to mediate recognition of aggregated proteins with conformational and sequence specificity. Our proposal is based on our recent discovery that single-domain antibodies can be designed to recognize Aß42 oligomers and fibrils using the same molecular interactions mediating Aßaggregation associated with Alzheimer's disease (Perchiacca et al., PNAS, 2012). We find that hydrophobic Aß peptides can be grafted into a single CDR loop, and the resulting Grafted AMyloid-Motif AntiBODIES (gammabodies) bind to Aß oligomers and fibrils with nanomolar affinity. Based on these discoveries, we posit that additional Aß peptides capable of mediating gammabody binding can be predicted based on their relative amyloidogenicity. We also hypothesize that the binding affinity of gammabodies will be maximal at small to intermediate CDR lengths that are sufficiently long to display Aß self-recognition peptides but not long enough to disfavor binding due to increased entropy. In addition, we posit that our design approach is not limited to Aßand can be extended to other amyloidogenic polypeptides, including IAPP (type 2 diabetes) and α-synuclein (Parkinson's disease). Finally, we hypothesize that even higher-affinity gammabodies can be designed by grafting multiple amyloidogenic peptides into anti-parallel CDRs that are oriented in the same manner as the corresponding peptides at the growing (templating) ends of fibrils. Therefore, in Aim 1, we propose to determine how the length and sequence of CDR3 impacts the binding affinity and specificity for two Aß gammabodies (Aß15-24 and Aß33-42). Then, in Aim 2, we propose to evaluate our predictions of additional Aß peptides that mediate gammabody binding to Aßaggregates when grafted into CDR3. Next, in Aim 3, we propose to extend the analysis performed in Aims 1 and 2 to evaluate our predictions of peptide segments from two other amyloid-forming polypeptides (α-synuclein and IAPP) that mediate gammabody binding to their corresponding aggregated conformers when grafted into CDR3. Finally, in Aim 4, we propose to evaluate whether the affinity of the Aßand IAPP gammabodies developed in Aims 1-3 can be increased by grafting two different amyloidogenic peptides into anti-parallel CDRs to match the orientation of the corresponding peptides at the growing ends of fibrils. A significant outcome of our studies will be the elucidation of how self-complementary, amyloidogenic peptides can be used to mediate antibody-antigen recognition. We expect that our findings will lead to rules for designing of similar single- and multidomain antibodies with specificity for diverse amyloidogenic proteins, including those linked to human aggregation disorders such as Huntington's and prion diseases.

描述（申请人提供）：生物分子研究的一大挑战是合理设计以高亲和力和特异性结合靶抗原的抗体。本提案的目标是阐明抗体互补决定区（CDR）的设计原则。我们的建议基于我们最近的发现，即单域抗体可以设计来识别 Aß42 寡聚物和使用与阿尔茨海默氏病相关的相同分子相互作用介导 Aß 聚集（Perchiacca 等人，PNAS，2012）我们发现疏水性 Aß 肽可以移植到单个 CDR 环中，并且所得的移植 AMyloid-Motif AntiBODIES（gammabody）结合。基于这些发现，我们假设额外的 Aß 具有纳摩尔亲和力。能够介导伽马体结合的肽可以根据其相对的淀粉样蛋白形成性来预测，我们还发现，伽马体的结合亲和力在小到中等的CDR长度下将是最大的，该长度足够长以显示Aß自我识别肽，但又不足以长到不受欢迎。此外，我们认为我们的设计方法不限于 Aß，并且可以扩展到其他淀粉样蛋白生成多肽，包括 IAPP（2 型）。最后，我们追求通过将多个淀粉样蛋白肽移植到与生长时相应肽相同的方向的反平行 CDR 中，可以设计出更高亲和力的伽马抗体。因此，在目标 1 中，我们建议确定 CDR3 的长度和序列如何影响两个 Aß 的结合亲和力和特异性。然后，在目标 2 中，我们建议评估我们对嫁接至 CDR3 时介导伽玛体与 Aß 聚集体结合的其他 Aß 肽的预测。在目标 1 和 2 中进行，以评估我们对来自其他两种淀粉样蛋白形成多肽的肽段的预测最后，在目标 4 中，我们建议评估目标 1-3 中开发的 Aß 和 IAPP 伽玛体的亲和力是否可以通过移植来增加。我们的研究的一个重要成果是，将两种不同的淀粉样肽形成反平行 CDR，以匹配原纤维生长末端相应肽的方向。我们希望我们的研究结果能够阐明如何使用自我互补的淀粉样蛋白肽来介导抗体-抗原识别，从而设计出对不同的淀粉样蛋白（包括那些相关的淀粉样蛋白）具有特异性的类似单域和多域抗体。人类聚集性疾病，如亨廷顿病和朊病毒病。