CRUI: Quantification of Metal Transfer From Metallothionein to Apometalloproteins Using Voltammetry Combined On Line with HPLC/ICP-MS

生命的进化与金属有着密切的联系，因此，进化过程有选择地加入特定的金属，以利用这些金属给生物分子带来的额外化学特性，这并不奇怪。因此，锌或铜金属的掺入可能赋予受体分子额外的立体可能性、催化活性或氧化还原特性，并且已知这些金属蛋白控制着重要的生物过程，如基因表达、呼吸和酸碱平衡。一种细胞内蛋白被认为参与了金属硫蛋白的所有这些过程，尽管这种蛋白控制细胞金属稳态的机制尚不清楚。将开发一种涉及直接耦合电化学（EC）、高效液相色谱（HPLC）和电感耦合等离子体质谱（ICP-MS）的新技术（EC/HPLC/ICP-MS）来进行一系列实验，这些实验被集体设计来确定(i)谷胱甘肽和氧化还原条件的相对重要性，这些条件是在复杂的细胞质环境中导致金属硫蛋白和载脂蛋白之间必需金属的提供和接受所必需的；（ii）谷胱甘肽二硫化物或氧化条件是否会导致金属硫蛋白释放Cd和其他生理上有毒的金属，从而导致随后与目标大分子的非特异性结合。

Life has evolved in close association with metals and it is not surprising, therefore, that evolutionary processes have selectively incorporated specific metals to take advantage of the additional chemical attributes that these metals bring to biological molecules. Thus, the incorporation of Zn or Cu metal may confer additional steric possibilities, catalytic activity or redox properties to the acceptor molecule and these metalloproteins are known to control important biological processes as varied as gene expression, respiration and acid/base balance.One intracellular protein that has been advocated to be involved in all of these processes in metallothionein, although the mechanisms by which this protein controls cellular metal homeostasis is unclear. A novel technique (EC/HPLC/ICP-MS) involving directly coupling electrochemistry (EC), high performance liquid chromatography (HPLC) and inductively coupled plasma mass spectroscopy (ICP-MS) will be developed to conduct a series of experiments that have been collectively designed to determine (i) the relative importance of glutathione and redox conditions necessary to cause the donation and acceptance of essential metals between metallothionein and apoenzymes within a complex cytoplasmic milieu; (ii) whether glutathione disulfide or oxidizing conditions can lead to the release of Cd and other physiologically toxic metals from metallothionein causing subsequent non-specific binding to target macromolecules.