NMR STUDIES OF METALLOTHIONEIN STRUCTURE AND REACTIVITY

金属硫蛋白结构和反应性的核磁共振研究

• 批准号: 3251873
• 负责人: JAMES D OTVOS
• 金额: $ 11.81万
• 依托单位: NORTH CAROLINA STATE UNIVERSITY RALEIGH
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-23 至 1993-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3251873
• 关键词: cadmium; chemical structure function; copper; detoxification; high performance liquid chromatography; isomer; laboratory rabbit; ligands; metal metabolism; metal poisoning; metallothionein; nuclear magnetic resonance spectroscopy; radiotracer; sheep; zinc

This proposal sets forth an integrated set of structural and chemical studies to elucidate biologically relevant structure- reactivity correlations between the multiple polymorphic forms (isoforms) of the metal binding protein, metallothionein (MT). This protein is a normal constituent of mammalian tissues and it or related structures are found throughout nature. It is the principal intracellular binding site for the environmentally important toxic heavy metal, cadmium, and is thought to provide the means for its detoxification. A central role is also certain for MT in the metabolism of the essential metals Zn and Cu. Depending on the tissue and physiological status of the organism in which it is found, there are multiple isoforms of MT expressed and these most often contain more than one type of metal. The overall goal of the proposed research is to rationalize on the basis of detailed solution structural studies any differences among the isoforms in their reactivity in ligand exchange and interprotein metal exchange reactions thought to be undergone by the protein in vivo. The structural probes to be used are 113Cd and 2H NMR and they will be employed interactively to provide complementary information regarding the environments of the metals at each of the sites in the two cluster domains and the protein structure surrounding these sites. The following specific goals will be pursued: 1) to document structural differences between the multiple MT isoforms from rabbit and sheep liver which appear to alter their modes of interaction with Cd and Zn, 2) to characterize any differences ln reactivity between the isoforms in ligand exchange and interprotein metal exchange reactions, 3) to characterize the mixed-metal products resulting from Cu(I) displacement of Cd and Zn from MT and direct metal exchange between CuMT and CdMT and ZnMT, and 4) to assess the biological relevance of the reactions in 3) by comparing their products to those of native rabbit liver Cu, ZnMT.

该提案提出了一套完整的结构性和 用于阐明生物相关结构的化学研究- 多种多态形式之间的反应性相关性 金属结合蛋白的亚型，金属硫蛋白(MT)。 这种蛋白质是哺乳动物组织的正常成分，它 或者相关的结构在自然界中随处可见。它是 环境中主要的细胞内结合部位 重要的有毒重金属镉，被认为提供了 它的解毒方法。一个核心角色也是肯定的 MT在必需金属锌和铜的代谢中的作用。取决于 关于它所在的生物体的组织和生理状态 发现，有多种MT亚型表达，这些 大多数都含有不止一种类型的金属。总目标 建议研究的基础是在合理化的基础上详细说明 溶液结构研究中异构体之间的任何差异 它们在配体交换和蛋白间金属交换中的反应性 被认为是蛋白质在体内发生的反应。这个 将使用的结构探针是~(113)Cd和~2H核磁共振，它们将是 以交互方式使用以提供补充信息 关于#年每个地点的金属环境 这两个簇结构域及其周围的蛋白质结构 网站。将追求以下具体目标：1) 记录多个MT亚型之间的结构差异 来自兔和羊的肝脏，它们似乎改变了它们的 与Cd和Zn的相互作用，2)表征N的任何差异 配基交换异构体与蛋白质间的反应性 金属交换反应，3)混合金属的表征 铜(I)置换金属镉和锌的产物 CuMT与CdMT和ZnMT之间的直接金属交换，以及4) 通过比较来评估3)中反应的生物学相关性 他们的产品与天然兔肝铜、锌的产品相比较。