Structure and Inhibition of Amyloid in Alzheimer's Disease

我们的假设是，缺乏药物来阻止阿尔茨海默病在很大程度上源于无知 最相关的药物靶点的结构：蛋白质tau和 β-淀粉样蛋白在这里，我们建议扩展我们对淀粉样纤维结构的研究， 低聚物，以实现抑制化合物的基于结构的设计。对于我们提出的每一个 在项目中，结构确定之后将是一种或多种抑制剂的基于结构的设计。 然后将测定每种抑制剂在体外抑制聚集体形成的有效性， 抑制细胞模型中的毒性。然后将在动物模型中评估最有效的抑制剂 我们的合作者。我们的项目包括：（1）确定tau寡聚体的结构，这种寡聚体可以在细胞间传播tau，并随后设计寡聚化抑制剂;（2）基于我们新确定的淀粉样蛋白形成蛋白的结构，设计tau聚集的抑制剂。 具有序列VQIINK的tau片段;（3）通过抑制性单结构域的核糖体展示的进化 针对tau聚集体的抗体，这些抗体有可能穿透血脑， 屏障;（4）用序列优化β-淀粉样蛋白的20个残基片段的现有晶体 GKLVFFGENVGSNKGAIIGL，其似乎形成低聚物。改进后的水晶将在 通过结构测定和抑制剂设计;（5）β-淀粉样蛋白或其片段在一个 脂质环境，以了解其毒性功能;（6）结构测定， β-淀粉样蛋白片段与其假定的细胞表面受体结合，随后进行抑制剂设计;（7） 探索我们新发现的甲状腺素运载蛋白断裂片段的作用 增加β-淀粉样蛋白的低聚物并抑制毒性。这些项目中的每一个，如果成功的话，都开辟了一条可能的治疗阿尔茨海默病的途径。这些路径以前不可用，因为相关结构未知。我们发现决定淀粉样蛋白结构的主要障碍是晶体的微小尺寸。我们建议通过进一步利用电子衍射的先进方法来克服这一障碍。

Our hypothesis is that the lack of drugs to halt Alzheimer’s disease stems in large part from ignorance of the structures of the most pertinent drug targets: the aggregated forms of the proteins tau and beta-amyloid. Here we propose to extend our studies of the structures of amyloid fibrils and oligomers to enable structure-based design of inhibiting compounds. For each of our proposed projects, structure determination will be followed by structure-based design of one or more inhibitors. Then each inhibitor will be assayed for effectiveness in inhibiting aggregate formation in vitro and inhibiting toxicity in cell models. The most effective inhibitors will then be assessed in animal models of our collaborators. Among our projects are the following: (1) Structure determination of oligomers of tau that can seed spreading of tau from cell to cell, and subsequent design of an inhibitor of oligomerization; (2) Inhibitor design of tau aggregation based on our newly determined structure of the amyloid-forming segment of tau with sequence VQIINK; (3) Evolution by ribosome display of inhibiting single-domain antibodies against tau aggregates, with the possibility that these may penetrate the blood-brain- barrier; (4) Optimization of existing crystals of the 20 residue segment of beta-amyloid with sequence GKLVFFGENVGSNKGAIIGL, which seems to form an oligomer. Improved crystals will be followed by structure determination and inhibitor design; (5) Crystallization of beta-amyloid or its segments in a lipid environment to gain possible insight into its toxic function; (6) Structure determination of a segment of beta-amyloid bound to its putative cell-surface receptor, followed by inhibitor design; (7) Exploration of the action of our newly discovered segment of the protein transthyretin which breaks up oligomers of beta-amyloid and inhibits toxicity. Each of these projects, if successful, opens a path to a possible therapeutic agent against Alzheimer’s disease. These paths have not been previously available because the pertinent structures have been unknown. We find the principal barrier to determination of amyloid structures is the miniscule size of the crystals. We propose to surmount this barrier by further exploitation of advanced methods of electron diffraction.