CADMIUM, ZINC, METALLOTHIONEIN AND KIDNEY CYTOTOXICITY

该提案提出了综合的理化和生物 阐明生物学相关结构-功能的研究 金属结合蛋白，金属硫蛋白（Mt）。 这种蛋白质是哺乳动物组织的正常成分。 是 也是一个明确界定的网站， 重要的是，有毒的重金属镉在与细胞反应时结合。 多年的研究表明，MT在 锌、铜代谢及镉的生化毒理。 然而，其生物功能的性质，事实上， 化学性质不明确。 的总体目标 拟议的研究是了解金属配体化学， MT在锌、镉代谢中的生物学功能及其作用机制 这些是相互关联的。 四名共同调查员是独立的 互补研究领域的科学家：多核JDO 金属蛋白的核磁共振结构-功能研究 金属药物和蛋白质的无机和生物无机研究， SSB在培养和运输特性的检查 肾皮质细胞和DHP在细胞代谢中的作用 必需金属和有毒金属以及金属的生物无机研究 复合物和金属蛋白质。 作者的广泛，重叠 利益支持这一建议，并导致以下具体 目的：（1）详细了解配体取代化学 Zn-和Cd-Mt涉及小配体竞争 金属结合或脱辅基蛋白。 一旦这些同质的 金属硫蛋白的理解，研究的性质 混合金属，镉，锌-金属硫蛋白配体取代 化学. (II)利用肾皮质细胞模型， Zn-Mt的正常功能，可能涉及生物配体 取代反应。 (III)最后，为了研究 镉与这一系统有关，因为它们与锌-金属硫蛋白功能有关 在金属捐赠反应和镉的结合到其他网站 在牢房里 综合性实验是为了边学边做 在体外发生的MT的化学与 可能发生在细胞中。 化学研究预测， 利用对金属硫蛋白簇的详细了解 结构由113 Cd NMR提供。 他们将集中在小心 分光光度动力学研究，以了解机制 金属硫蛋白的配体取代反应。 肾 皮质细胞将被用作与以下高度相关的细胞模型： 镉毒理学。 为了将化学结果与细胞联系起来， Zn和Cd在细胞组分中的分布， 将使用放射性示踪剂进行分区， 大量的金属和蛋白质 会议将于 结合镉对皮层细胞影响的评估 功能

This proposal sets forth integrated physiochemical and biological studies to elucidate biologically relevant structure-function relationships of the metal binding protein, Metallothionein (Mt). This protein is a normal constituent of mammalian tissues. It is also the one well defined site to which the environmentally important, toxic heavy metal Cd binds as it reacts with cells. Years of study have demonstrated that Mt plays a central role in Zn and Cu metabolism and the biochemical toxicology of Cd. However, the nature of its biological functions and, indeed, chemical properties are ill defined. The overall goal of the proposed research is to understand the metal-ligand chemistry of Mt, its biological functions in Zn and Cd metabolism and how these are interrelated. The four co-investigators are independent scientists in complementary research area: JDO in multinuclear NMR structure-function studies of metalloproteins, CFS in inorganic and bioinorganic studies of metallo-drugs and proteins, SSB in the culture and examination of transport properties of kidney cortical cells, and DHP in the cellular metabolism of essential and toxic metals and bioinorganic studies of metal complexes and metallo-proteins. The author's broad, overlapping interests undergird this proposal and lead to the following specific aims: (I) To understand in detail the ligand substitution chemistry of Zn- and Cd-Mt involving either small ligands competing for the Mt-bound metal or apometallo-proteins. Once these homogenous metallothioneins are understood, to investigate the properties of mixed metal, Cd, Zn-metallothioneins in ligand substitution chemistry. (II) To use the kidney cortical cell model to study the normal functions of Zn-Mt, possibly involving biological ligand substitution reactions. (III) Finally, to study the interactions of Cd with this system as they relate to Zn-metallothionein function in metal donation reactions and to the binding of Cd to other sites in the cell. Integrated experiments are designed to study side by side the chemistry of Mt which occurs in vitro with that which may be occurring in cells. Chemical studies are predicted on and use the detailed understanding of metallothionein cluster structures provided by 113 Cd NMR. They will center on careful spectrophotometric kinetic studies to understand the mechanism of the ligand substitution reactions of metallothioneins. Kidney cortical cells will be used as a cellular model highly relevant to Cd toxicology. To relate the chemical results to cells, kinetics of distribution of Zn and Cd among cell components and compartments will be carried out using radiotracers to follow pools of metal and protein. Compartments will be carried out in conjunction with assessment of effects of Cd on cortical cell function.