Metastable Crystallins: Structure and Stabilization

描述（由申请人提供）：现在已知许多不同的疾病，包括白内障、某些类型的青光眼、阿尔茨海默病、糖尿病和癌症，仅举几例，都具有聚集、错误折叠或修饰的蛋白质沉积的共同特征。这组疾病的病理学标志是蛋白质聚集和沉积在特定细胞、组织或器官中。病理学的相似性表明，共同的原则，管理蛋白质相互作用的蛋白质错误折叠退行性疾病的基础。白内障是蛋白质错误折叠和聚集疾病的典型例子。白内障是世界上致盲的主要原因，其发展是透镜蛋白质的年龄相关性改变和聚集的结果。?-晶状体蛋白占成人透镜蛋白质的近40%，但其结构-功能尚未完全了解。像监护人一样的活动？晶体蛋白被认为在保持透镜透明度中起中心作用。在老化过程中，透镜晶状体蛋白经历截短，并且这些修饰与负责光散射的透镜晶状体蛋白聚集相关。这是公认的，增加？晶状体蛋白与聚集蛋白质的结合阻止了聚集和光散射的进一步增加。我们已经证明了？-晶状体蛋白亚基抑制变性蛋白的聚集。然而，充分发挥潜力？堆叠衍生肽（小分子伴侣）还有待实现。加强 基于我们对白内障形成中非天然相互作用的理解，我们提出了以下具体目标：目标1。识别序列参与异常相互作用？A-晶状体蛋白亚基导致蛋白质聚集在人类白内障？A-晶体蛋白突变体（？AR49C，？AF71V，？AG 98 R和？AR116H）。目标二。确定的机制和疗效？A-晶状体蛋白衍生的微型分子伴侣在防止亚稳态聚集中的作用？A-晶体蛋白（突变体和截短晶体蛋白）和恢复伴侣活性。具体目标将使用新型交联剂和质谱方法来实现。我们还将使用定点诱变和细胞培养表达和分析系统来确认交联数据。这些创新的研究将为我们提供新的见解，以了解蛋白质错误折叠疾病的潜在干预措施，不仅是眼睛，而且是身体的其他部位。

DESCRIPTION (provided by applicant): Many diverse diseases, including cataract, some types of glaucoma, Alzheimer disease, diabetes and cancer to name only a few, are now known to share the common feature of aggregated, misfolded or modified protein deposits. The pathological hallmark in this group of diseases is protein aggregation and deposition in specific cells, tissues or organs. The pathological similarities indicate that common principles that govern protein interactions underlie protein misfolding degenerative diseases. Cataract is a classic example of a protein misfolding and aggregation disease. Cataract, a major cause of blindness in the world, develops as a result of age-related modifications and aggregation of the lens proteins. ?-crystallin accounts for nearly 40% of the adult lens proteins but its structure-function is yet to be fully understood. The chaperone-like activity of ?-crystallin is believed to play a central role in maintaining lens transparency. During aging, lens crystallins undergo truncation and these modifications correlate with lens crystallin aggregations responsible for light scattering. It is well established that the addition of ?-crystallin to aggregating proteins stops a further increase in aggregation and light scattering. We have demonstrated that specific sequences in ?-crystallin subunits suppress aggregation of denaturing proteins. However, the full potential of ?-crystallin-derived peptides (mini-chaperones) is yet to be realized. To enhance our understanding of the role of non-native interactions in cataract formation, we propose the following specific aims: Aim 1. Identify the sequences involved in abnormal interactions of ?A-crystallin subunits that lead to protein aggregation in human cataract-causing ?A-crystallin mutants (?AR49C, ?AF71V, ?AG98R and ?AR116H) using novel deuterated cross linkers, biotynylated reagents and peptide arrays. Aim 2. Determine the mechanism and efficacy of ?A-crystallin-derived mini-chaperone in preventing the aggregation of metastable ?A- crystallins (mutants and truncated crystallins) and restoring chaperone activity. The specific aims will be accomplished using novel cross-linkers and mass spectrometric methods. We will also use site-directed mutagenesis and cell culture expression and analysis systems to confirm the cross linking data. These innovative studies will give us new insights into potential interventions for protein misfolding diseases, not only of the eye but also of other parts of the body.