Aggregation of Deamidated Crystallins as a Major Cause of Cataracts

脱酰胺化晶状体蛋白的聚集是白内障的主要原因

• 批准号: 10298668
• 负责人: KIRSTEN Jeanne LAMPI
• 金额: $ 39.85万
• 依托单位: OREGON HEALTH & SCIENCE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-30 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10298668
• 关键词: Address; Age; Age of Onset; Aging; Antioxidants; Cataract; Cell Nucleus; Chemicals; Crystalline Lens; Crystallins; Data; Deuterium; Development; Disease; Distant; Disulfides; Environment; Etiology; Glutamine; Glutathione; Goals; Grant; Human; Hydrogen; In Vitro; Laboratories; Lead; Link; Mass Spectrum Analysis; Mediating; Methods; Modification; Nuclear; Oxides; Pathway interactions; Pharmaceutical Preparations; Post-Translational Protein Processing; Predisposition; Process; Protein Dynamics; Proteins; Reporting; Resolution; Structure; Testing; Work; age related; aged; amyloid fibril formation; biophysical properties; crosslink; deamidation; dimer; disulfide bond; experimental study; gamma-Crystallins; in vivo; insight; ion mobility; lens; light scattering; model development; molecular modeling; non-Native; oxidation; peptide A; protein aggregation; response; therapeutic development

Project Summary: Our laboratories have focused on the most prevalent chemical modifications that we have identified to be associated with the insoluble proteins present in the nucleus of the lens- deamidation and oxidation. These modifications are most relevant to age-related nuclear cataract, by far the most common type of cataract. In this proposed work, we will examine the interplay between deamidation and oxidation in order to mimic the age-related processes in the lens. Although the lens environment is normally in a reduced state, oxidation of sulfhydryls in crystallins has long been associated with age-related cataract as the pool of lens glutathione diminishes with aging in the center of the lens. The formation of non-native, disulfide crosslinked crystallin subunits via the oxidation of Cys residues is therefore anticipated to be a key process leading to the aggregation and insolubilization of lens proteins. In Aim 1, we will determine how specific, age-related deamidations in γS promote its aggregation by identifying non-native disulfide bond formed in response to combined deamidation and oxidation. In Aim 2, we will test the hypothesis that non-native disulfide bond formation leads to higher ordered oligomers of γS. While the focus of Aims 1 and 2 is the oxidation of deamidated γS, Aim 3 explores whether these age-related modifications in γS lead to non-native crosslinks between γ- and β-crystallin subunits and thereby disrupt the native quaternary arrangement of the crystallins. Overall, these findings will elucidate how deamidation, a spontaneous modification, contributes to the oxidation-driven aggregation cascade that underlies age-related nuclear cataract. Establishing that deamidation mediates its effects predominantly via augmenting the oxidation of crystallin proteins will provide a robust model for the development of therapeutic strategies aiming to delay the onset of age-related nuclear cataract by restoring the antioxidant levels of the lens. The work will also have significant implications for several other diseases where deamidation and oxidation of long-lived proteins is associated with amyloid fibril formation.

项目摘要： 我们的实验室专注于我们确定为的最普遍的化学修饰 与透镜 - 脱酰化和氧化核中存在的不溶性蛋白有关。这些 修改与年龄相关的核白内障最相关，这是迄今为止最常见的白内障类型。 这项提出的工作，我们将检查死亡和氧化之间的相互作用，以模仿 镜头中与年龄相关的过程。尽管镜头环境通常处于降低的状态，但氧化 水晶蛋白中的亚硫烯丙烯素长期以来与年龄相关性白内障相关 随着镜头中心的衰老而减少。形成了非本地的二硫键交联晶体 因此 晶状体蛋白的聚集和不阐明。在AIM 1中，我们将确定与年龄相关的特异性 γs中的脱胺通过确定响应于 结合死亡剂和氧化。在AIM 2中，我们将测试非本地二硫键的假设 形成导致γs的较高有序的低聚物。目标1和2的焦点是氧化 脱膜γs，AIM 3探讨了这些与年龄相关的修饰是否导致非本地交联 γ-和β-晶状体亚基之间，从而破坏了结晶蛋白的天然第四纪排列。 总体而言，这些发现将阐明死亡化（发起的修改）如何有助于 氧化驱动的聚集级联反应是与年龄相关的核白内障的基础。建立这个 脱氨酸主要通过增强结晶蛋白的氧化而主要介导其作用 用于制定治疗策略的强大模型旨在延迟与年龄相关的核的发作 白内障通过恢复镜头的抗氧化剂水平。这项工作还将对 其他几种疾病，其中长寿命蛋白的死亡和氧化与淀粉样蛋白纤维有关 形成。