Metastable Crystallins: Structure and Stabilization

描述（由申请人提供）：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，现在已知具有聚集，错误折叠或修饰的蛋白质沉积物的共同特征。这组疾病的病理标志是蛋白质聚集和沉积在特定的细胞、组织或器官中。病理上的相似性表明，控制蛋白质相互作用的共同原则是蛋白质错误折叠退行性疾病的基础。白内障是一种典型的蛋白质错误折叠和聚集性疾病。白内障是世界上致盲的一个主要原因，是由于与年龄相关的晶状体蛋白的改变和聚集而发展起来的。α-晶体蛋白占成人晶状体蛋白的近40%，但其结构功能尚不完全清楚。的监护人式活动

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. α-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 α-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 α-crystallin to aggregating proteins stops a further increase in aggregation and light scattering. We have demonstrated that specific sequences in α-crystallin subunits suppress aggregation of denaturing proteins. However, the full potential of α-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 αA-crystallin subunits that lead to protein aggregation in human cataract-causing A-crystallin mutants (αAR49C, αAF71V, αAG98R and αAR116H) using novel deuterated cross linkers, biotynylated reagents and peptide arrays. Aim 2. Determine the mechanism and efficacy of αA-crystallin-derived mini-chaperone in preventing the aggregation of metastable αA- 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.