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: 3251874
• 负责人: JAMES D OTVOS
• 金额: $ 12.28万
• 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 1994-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3251874
• 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和 化学研究，以阐明生物相关结构- 多种多晶型之间的反应性相关性 金属结合蛋白（金属硫蛋白（MT））的亚型。 这种蛋白质是哺乳动物组织的正常成分， 或相关结构在自然界中随处可见。 是 主要的细胞内结合位点的环境 重要的有毒重金属，镉，被认为是提供了 它的解毒方法。 中心作用也是肯定的， MT参与必需金属Zn和Cu的代谢。 取决 对组织和生理状态的有机体，其中它 发现，有多种MT亚型表达，这些 大多数通常包含一种以上的金属。 总目标 建议的研究是合理化的基础上，详细 溶液结构研究异构体之间的任何差异， 它们在配体交换和蛋白质间金属交换中的反应性 被认为是蛋白质在体内经历的反应。 的 使用的结构探针是113 Cd和2 H NMR，并且它们将 互动地提供补充信息 关于金属的环境在每个网站， 两个簇结构域和围绕它们的蛋白质结构 网站. 具体目标如下：1） 记录多种MT亚型之间的结构差异 从兔子和绵羊的肝脏，似乎改变他们的模式， 与Cd和Zn的相互作用，2）表征任何差异， 配体交换和蛋白质间异构体之间的反应性 金属交换反应，3）表征混合金属 Cu（I）置换MT中Cd和Zn的产物， CuMT与CdMT和ZnMT之间的直接金属交换，以及4） 通过比较，评估3）中反应的生物学相关性 其产物与天然兔肝Cu、ZnMT的产物进行了比较。