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: 3251871
• 负责人: JAMES D OTVOS
• 金额: $ 7.74万
• 依托单位: UNIVERSITY OF WISCONSIN MILWAUKEE
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-04-01 至 1989-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3251871
• 关键词: cadmium; chemical structure function; copper; detoxification; laboratory rabbit; ligands; metal metabolism; metal poisoning; metallothionein; nuclear magnetic resonance spectroscopy; radiotracer; zinc

This proposal sets forth an integrated series of chemical and structural studies to elucidate biologically relevant structure-reactivity correlations of the metal binding protein, metallothionein (MT). This protein is a normal constituent of mammalian tissues and it or related structures are found in a wide vartiety of non-mammalian species. It is the principal intracellular binding site for the environmentally important, toxic heavy metal Cd and is thought to provide the means for its detoxification. A central role has also been proposed for MT in the metabolism of the essential metals Zn and Cu. Depending on the physiological status of the organism in which it is found, the protein can contain more than one type of metal and, in fact, is most often found in a mixed-metal state. The overall goal of the proposed research is to rationalize on the basis of in vitro metal exchange reactions how these mixed metal MTs are formed in vivo and to determine the structural and chemical conseqeueces of shared occupancy of the metal-thiolate clusters by different metals. The structural probes to be used are 113Cd and 1H NMR and they will be interactively employed to provide complementary information regarding the environments of the metals at each of the seven binding sites and the protein structure surrounding these sites. The following specific goals will be pursued: (1) to determine structural diffrences that exist between MT isoproteins and between the two metal-thiolate clusters as a function of the metal bound, (2) to characterize the binding of Cd to apoMT, (3) to investigate the kinetics and mechanisms of reactions which produce mixed Cd,ZnMTs, (4) to characterize the products of in vitro reactions which produce mixed Cu,ZnMTs and Cu,CdMTs, and (5) to assess the biological relevance of these reactions by comparing their products to those of native rabbit liver Cu,ZnMT.

该提案提出了一系列综合的化学和结构 阐明生物学相关结构-反应性的研究 金属结合蛋白金属硫蛋白（MT）的相关性。 这 蛋白质是哺乳动物组织的正常成分， 结构存在于多种非哺乳动物物种中。 是 主要的细胞内结合位点， 有毒的重金属镉，并被认为提供了手段， 解毒 还提议让监测组发挥核心作用， 必需金属锌和铜的代谢。 取决于 蛋白质可以在其所处的生物体的生理状态下， 含有一种以上的金属，事实上，最常见于 混合金属状态 拟议研究的总体目标是 合理化的基础上，在体外金属交换反应如何， 在体内形成混合金属MT，并确定其结构和 金属硫醇盐簇的共享占有的化学consequeeces的 不同的金属 所用的结构探针是113 Cd和1H NMR 它们将被交互式地使用， 关于七个金属环境的信息 结合位点和围绕这些位点的蛋白质结构。 的 具体目标如下：（1）确定结构 MT同工蛋白之间以及两者之间存在的差异 金属-硫醇盐簇作为结合的金属的函数，（2） 研究镉与apoMT结合的动力学 以及产生混合Cd、ZnMTs的反应机理，（4）， 表征产生混合物的体外反应产物 Cu，ZnMT和Cu，CdMT，以及（5）评估这些的生物相关性 通过比较它们的产物与天然兔肝的产物的反应， Cu、ZnMT。