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（由适用提供）：生物分子研究中的一个巨大挑战是合理设计抗体，该抗体与具有高亲和力和特异性的靶抗原结合。该提案的目的是阐明设计抗体片段的完成区域（CDR）的原则，以介导具有构象和序列特异性的聚合蛋白的识别。我们的建议是基于我们最近发现的，即单域抗体可以设计为使用与阿尔茨海默氏病有关的介导的Aβ聚集的相同分子相互作用识别Aβ42低聚物和原纤维（Perchiacca等，PNAS，PNAS，2012年）。我们发现，疏水性Aβ肽可以接枝到单个CDR环中，并将所得的接枝淀粉样淀粉样蛋白抗体抗体（γ型）与Aβ低聚物和具有纳摩尔亲和力的原纤维结合。基于这些发现，我们还假设，在较小至中间的CDR长度上，γ代造型的结合亲和力将是最大的，这些长度足够长，足以显示Aβ自我识别肽，但不足以使由于熵的增加而不受任何影响。此外，我们认为我们的设计方法不仅限于Aβ，并且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α-突触核蛋白（帕金森氏病）。最后，我们假设甚至可以通过将多种淀粉样蛋白生成肽嫁接到抗平行的CDR中来设计，这些链球菌的定向方式与原纤维的生长（模板）末端相同的方式相同。因此，在AIM 1中，我们建议确定CDR3的长度和序列如何影响两种Aβγ型的结合亲和力和特异性（Aβ15-24和Aβ33-42）。然后，在AIM 2中，我们建议评估我们对接枝到CDR3时与Aβ聚集体结合的其他Aβ肽的预测。接下来，在AIM 3中，我们建议扩展在AIMS 1和2中进行的分析，以评估我们对其他两个淀粉样淀粉样蛋白形成多肽（α-突触核蛋白和IAPP）的肽片段的预测，这些多肽（α-突触核蛋白和IAPP）介导γ型γ型γ与将其相构构结合到CRAFT3中时，它们与它们的记录构型结合。最后，在AIM 4中，我们建议通过将两种不同的淀粉样蛋白生成petides接种到抗平行的CDR中，以增加AIMS 1-3中Aβ和IAPPγ的亲和力是否可以增加，以匹配纤维化生长末端的相应Petides的方向。我们的研究的一个重大结果将是阐明如何使用自我平衡的淀粉样蛋白生成宠物来介导抗体 - 抗原识别。我们预计我们的发现将导致设计具有特异性的类似单一和多域抗体的规则，这些抗体具有特异性，包括潜水员淀粉样蛋白的蛋白质，包括与人类聚集障碍（如亨廷顿和prion疾病）相关的蛋白。