Inhibition of amyloidogenic Islet Amyloid Polypeptide aggregation with designed c

描述（由申请人提供）：37-氨基酸多肽胰岛淀粉样多肽（IAPP，胰淀素）的聚集，作为不溶性淀粉样蛋白或作为小的寡聚体，似乎在2型糖尿病中胰岛细胞的死亡中起直接作用。虽然已知IAPP是2型糖尿病淀粉样蛋白的主要成分，但负责这种聚集的分子相互作用尚未完全了解。已知在约95%的2型糖尿病患者中发现IAPP作为淀粉样蛋白的细胞外沉积物。IAPP在体外也被证明是一种毒性剂，当加入到人类胰岛细胞中时。虽然目前还不清楚IAPP的自组装如何导致疾病的发展，但最近的研究表明，低级蛋白质聚集体（2至10个自组装蛋白质）的形成导致细胞毒性并最终导致疾病的进展。预防这些有毒寡聚物的形成可以预防或减缓2型糖尿病的进展。我们建议使用荧光屏来识别抑制淀粉样蛋白形成IAPP自组装的肽和小分子。在该筛选中，IAPP基因与增强型绿色荧光蛋白（EGFP）基因遗传融合。将IAPP-EGFP融合蛋白在E. IAPP聚集的自然倾向阻止了EGFP的折叠和荧光。然而，在存在防止淀粉样蛋白聚集的物质的情况下，融合的EGFP可以正确折叠并发出绿色荧光。我们建议筛选设计的组合肽库和小分子，以分离和鉴定抑制淀粉样蛋白形成的物质，因此，显示出作为预防或减缓2型糖尿病进展的治疗剂的潜力。 公共卫生相关性：小肽胰岛淀粉样多肽（IAPP，胰淀素）的聚集似乎与胰岛细胞的损失和2型糖尿病的发病直接相关。我们建议筛选短肽和小分子文库，以确定抑制淀粉样蛋白形成的物质。这些实验有可能发现新的治疗药物，用于预防或减缓2型糖尿病的进展。

DESCRIPTION (provided by applicant): The aggregation of the 37-amino acid polypeptide Islet Amyloid Polypeptide (IAPP, amylin), as either insoluble amyloid or as small oligomers, appears to play a direct role in the death of pancreatic ¿-islet cells in type 2 diabetes. While IAPP has been known to be the primary component of type 2 diabetes amyloid, the molecular interactions responsible for this aggregation are not fully understood. It is known that IAPP is found as extracellular deposits of amyloid in approximately 95% of patients afflicted with type 2 diabetes. IAPP has also been shown to be a toxic agent in vitro when added to human islet ¿-cells. While it remains unclear how self-assembly of IAPP leads to the development of disease, recent studies have suggested that the formation of lower order protein aggregates (two to ten self-assembled proteins) leads to cellular toxicity and ultimately to the progression of disease. Preventing the formation of these toxic oligomeric species may prevent, or slow, the progression of type 2 diabetes. We propose to use a fluorescent screen to identify peptides and small molecules that inhibit the self-assembly of amyloid-forming IAPP. In this screen, the gene for IAPP is genetically fused to the gene for enhanced green fluorescent protein (EGFP). When the IAPP-EGFP fusion protein is expressed in E. coli the natural propensity of IAPP to aggregate precludes EGFP from folding and fluorescing. However, in the presence of substances that prevent amyloid aggregation, the fused EGFP can fold properly and fluoresce green. We propose to screen designed combinatorial peptide libraries and small molecules to isolate and identify substances that inhibit amyloid formation and, therefore, show potential as therapeutic agents for preventing or slowing the progression of type 2 diabetes. PUBLIC HEALTH RELEVANCE: The aggregation of the small peptide Islet Amyloid Polypeptide (IAPP, amylin) appears to be directly related with loss of ¿-cells and the onset of type 2 diabetes. We propose to screen libraries of short peptides and small molecules to identify substances that inhibit amyloid formation. These experiments have the potential to discover new therapeutic agents for preventing, or slowing, the progression of type 2 diabetes.