CATARACT RELATED MODIFICATIONS OF HUMAN LENS CRYSTALLINS

描述（研究者摘要）：白内障，一种常见的 衰老，在患有尿毒症的人中发生率增加， 糖尿病或慢性腹泻。 预防性保健的合理发展 建议和治疗药物一直受到缺乏 在分子水平上对透镜进行共价修饰的知识 引起或伴随白内障的蛋白质。 拟议 研究将通过使用基于以下内容的新分析方法来满足这一需求： 用质谱法分析从正常人、老年人和 人类白内障的晶状体 在第一层次的分析中， 质谱，电喷雾电离质谱（ESIMS），将 用于测定透镜蛋白的分子量， 精度为0.02%（5个质量单位）。 然后透镜蛋白将 蛋白水解片段化成肽，其分子量将 用直接耦合的微孔以0.3质量单位的精度测定 HPLC快速原子轰击质谱法。 的分子量 透镜蛋白和蛋白水解肽，以及它们的层析方法， 和电泳特性，将用于识别，在分子 水平、正常和共价修饰的透镜蛋白。一个池的结果 正常人的晶状体将被用来建立一个数据库， 将比较来自老化和白内障晶状体的类似分析。 分子量不在参考文献中的蛋白质和肽 数据库将被认为经历了共价修饰。 与尿毒症、糖尿病和慢性腹泻相关的白内障晶状体 将通过相同的程序进行研究，以便共价修饰的蛋白质 并且可以辨别每种类型的白内障特有的肽。 透镜 经历了衰老特有的共价修饰的蛋白质， 白内障的特殊形式将通过各种显微镜进行研究。 分析方法，以确定在分子水平上的类型 修饰以及蛋白质上的特定位点， 经过修改。

DESCRIPTION (Investigator's Abstract): Cataract, a common disorder of aging, occurs with increased incidence among persons afflicted with uremia, diabetes, or chronic diarrhea. The rational development of preventive recommendations and therapeutic drugs has been hampered by a lack of knowledge at the molecular level about covalent modifications to lens proteins that either cause or accompany cataract. The proposed investigation will address this need by using new analytical methods based on mass spectrometry to analyze proteins isolated from normal, aged, and cataractous human lenses. In the first level of analysis, a new form of mass spectrometry, electrospray ionization mass spectrometry (ESIMS), will be used to determine the molecular weights of lens proteins with an accuracy of 0.02 percent (5 mass units). Lens proteins will then be proteolytically fragmented into peptides whose molecular weights will be determined with an accuracy of 0.3 mass units by directly-coupled microbore HPLC fast atom bombardment mass spectrometry. The molecular weights of the lens proteins and proteolytic peptides, as well as their chromatographic and electrophoretic properties, will be used to identify, at the molecular level, normal and covalently modified lens proteins. Results for a pool of normal human lenses will be used to make a data bank with which results from similar analyses of aged and cataractous lenses will be compared. Proteins and peptides with molecular weights that are not in the reference data bank will be considered to have undergone covalent modification. Cataractous lenses associated with uremia, diabetes, and chronic diarrhea will be studied by the same procedure so that covalently modified proteins and peptides unique to each type of cataract can be discerned. Lens proteins that have undergone covalent modifications unique to aging and specific forms of cataract will be investigated by a variety of micro analytical methods to identify at the molecular level the type of modification as well as the specific site on the protein which has undergone modification.