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: 8823800
• 负责人: Peter M Tessier
• 金额: $ 26.41万
• 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/8823800
• 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 Aβ42 oligomers and fibrils using the same molecular interactions mediating Aβ aggregation associated with Alzheimer's disease (Perchiacca et al., PNAS, 2012). We find that hydrophobic Aβ peptides can be grafted into a single CDR loop, and the resulting Grafted AMyloid-Motif AntiBODIES (gammabodies) bind to Aβ oligomers and fibrils with nanomolar affinity. Based on these discoveries, we posit that additional Aβ 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 Aβ 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 Aβ and 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 Aβ gammabodies (Aβ15-24 and Aβ33-42). Then, in Aim 2, we propose to evaluate our predictions of additional Aβ peptides that mediate gammabody binding to Aβ aggregates 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 Aβ and 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 Aβ42 寡聚物和使用与阿尔茨海默病相关的相同分子相互作用介导 Aβ 聚集（Perchiacca 等人，PNAS，2012）我们发现疏水性 Aβ 肽可以移植到单个 CDR 环中，并产生移植的 AMyloid-Motif AntiBODIES（gammabodies）。基于这些发现，我们认为其他 Aβ 肽能够以纳摩尔亲和力与 Aβ 寡聚物和原纤维结合。我们还发现，伽玛体的结合亲和力在小到中等的 CDR 长度下将达到最大，该长度足够长以显示 Aβ 自我识别肽，但又不足以长到不利于结合。此外，我们认为我们的设计方法不仅限于 Aβ，还可以扩展到其他淀粉样蛋白生成多肽，包括 IAPP（2 型糖尿病）和最后，我们追求通过将多个淀粉样蛋白生成肽移植到反平行 CDR 中来设计甚至更高亲和力的伽马抗体，这些 CDR 的方向与生长（模板）末端的相应肽相同。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种 Aβ 伽玛抗体的结合亲和力和特异性。 （Aβ15-24 和 Aβ33-42）。然后，在目标 2 中，我们建议评估我们对移植到 CDR3 时介导伽玛体与 Aβ 聚集体结合的其他 Aβ 肽的预测。在目标 1 和 2 中进行，以评估我们对来自另外两种淀粉样蛋白形成多肽（α-突触核蛋白和 IAPP）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 Aβ 和 IAPP 伽玛体的亲和力是否可以通过将两种不同的淀粉样蛋白生成肽移植到抗-Aβ 和 IAPP 中来增加。平行 CDR 来匹配原纤维生长末端相应肽的方向，我们研究的一个重要成果将是阐明如何进行。自我互补的淀粉样蛋白肽可用于介导抗体-抗原识别，我们期望我们的发现将导致设计类似的单域和多域抗体的规则，这些抗体具有针对不同淀粉样蛋白的特异性，包括与人类聚集性疾病相关的蛋白。亨廷顿病和朊病毒病。