Toward Molecular-Scale Models of Congenital and Age-Related Cataract: a Concerted Computational and Experimental Approach

先天性和年龄相关性白内障的分子尺度模型：协调一致的计算和实验方法

• 批准号: 9225213
• 负责人: Douglas J Tobias
• 金额: $ 34.5万
• 依托单位: UNIVERSITY OF CALIFORNIA-IRVINE
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-03-01 至 2019-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9225213
• 关键词: Amino Acid Sequence; Automobile Driving; Biophysics; Blindness; Cataract; Complex Mixtures; Computer Simulation; Computing Methodologies; Coupled; Crowding; Crystalline Lens; Crystallins; Data; Development; Equilibrium; Future; Goals; Human; Individual; Investigation; Lead; Measurement; Methods; Modeling; Molecular; Molecular Chaperones; Monte Carlo Method; Mutation; NMR Spectroscopy; Nature; Neutrons; Organism; Point Mutation; Post-Translational Protein Processing; Precipitation; Prevention; Property; Protein Dynamics; Proteins; Relaxation; Research; Resolution; Roentgen Rays; Solubility; Structural Models; Structure; Techniques; Variant; age related; alpha-Crystallins; base; congenital cataract; experimental study; fiber cell; gamma-Crystallins; innovation; insight; lens; lens transparency; light scattering; molecular dynamics; molecular scale; mutant; nephelometry; novel therapeutics; prevent; protein aggregation; protein degradation; protein protein interaction; protein structure; public health relevance; single molecule; solid state nuclear magnetic resonance

 DESCRIPTION (provided by applicant): Cataract, an opacification of the eye lens caused by a loss of solubility of the crystallin proteins, is a leading cause of blindness worldwide. The overarching goal of the proposed research is to use computational modeling and a broad suite of biophysical experiments to gain new insight into cataract formation on the molecular level that could ultimately guide the development of new therapies for cataract prevention and treatment. The primary hypothesis driving the proposed research is that altered protein-protein interactions, resulting from point mutations (in the case of congenital cataract) or post- translational modifications (in the case of age-related cataract), lead to aggregation of the crystallins which, in turn, leads to loss of transparency in the lens. We propose a concerted experimental and computational investigation of protein structure, organization, and aggregation in solutions of human γD- and γS-crystallins. We will employ a multiscale computational modeling approach, consisting of Monte Carlo and atomistic molecular dynamics simulations, validated and refined using experimental data (NMR, light scattering, and small angle scattering), to gain molecular-scale insight into the interprotein interactions that stabilize concentrated solutions of wild-type γD- and γS- crystallins, or lead to the formation of insolubl aggregates in solutions of variants associated with congenital cataracts. The same approach will be applied in the first systematic computational and biophysical investigation of deamidated variants of γS- crystallin that mimic the changes observed in age-related cataract. Once the concerted application of MC simulations, biophysical experiments, small angle scattering measurements, and solution and solid-state NMR experiments has been developed for single-component γ-crystallin solutions, the approach will be applied to the determination of a molecular-level description of the interactions between αB-crystallins and wild-type γ-crystallin and their cataract-related variants. Thus, we will gain crucial insight into the chaperone function of the αB-crystallins, as well as the ability of the αB-crystallins to maintain the delicate balace of interactions that maintains the transparency of solutions of wild-type γ-crystallins.

 描述（由申请人提供）：白内障是由晶状体蛋白溶解度丧失引起的眼睛晶状体混浊，是全世界失明的主要原因。拟议研究的总体目标是利用计算模型和广泛的生物物理实验在分子水平上获得对白内障形成的新见解，最终指导白内障预防和治疗新疗法的开发。推动这项研究的主要假设是，点突变（先天性白内障）或翻译后修饰（年龄相关性白内障）导致蛋白质-蛋白质相互作用的改变，导致晶状体蛋白聚集，进而导致晶状体透明度丧失。我们建议对人类 γD- 和 γS- 晶状体蛋白溶液中的蛋白质结构、组织和聚集进行协调一致的实验和计算研究。我们将采用多尺度计算建模方法，包括蒙特卡罗和原子分子动力学模拟，并使用实验数据（NMR、光散射和小角散射）进行验证和完善，以获得分子尺度上对蛋白质间相互作用的深入了解，这些相互作用可以稳定野生型 γD- 和 γS- 晶状体蛋白的浓溶液，或导致在溶液中形成不溶性聚集体。 与先天性白内障相关的变异。同样的方法将应用于对γS-晶状体蛋白脱酰胺变体的首次系统计算和生物物理研究，模拟与年龄相关的白内障中观察到的变化。一旦针对单组分 γ-晶状体蛋白溶液开发了 MC 模拟、生物物理实验、小角散射测量以及溶液和固态 NMR 实验的协同应用，该方法将应用于确定 αB-晶状体蛋白和野生型 γ-晶状体蛋白及其白内障相关变体之间相互作用的分子水平描述。因此，我们将对伴侣功能有重要的了解 αB-晶状体蛋白的能力，以及 αB-晶状体蛋白维持微妙的相互作用平衡的能力，从而保持野生型 γ-晶状体蛋白溶液的透明度。