Abstract: With the aid of computer imaging, the structure models of Cd-thio clusters in Cd-metallothioneins are provided based on the propertiesof MT conformation and acquisition of the mutated protein are proposed. According to the results of calculation, it is difficult to add a cadimumion in α-domain without a drastic change of the peptide backbone and the structure of the cluster. However, it is possible to add a cadimum ion in β-domain by inserting or mutating a few amino acid residues.

Key words: metallothionein, design of MT molecular modification, Cd-thio cluster

摘要： 金属硫蛋白(MT)的三维结构已由二维NMR和X射线晶体衍射测定。本文使用PS-300图象显示仪及计算机Hydra程序，对MT分子进行改造设计，目的是探索提高MT与Cd，Hg结合能力的分子设计。计算表明，MT分子中α-domain很难再加入一个Cd原子，而β－domain有可能设计再加一个Cd，提出在第29位残基后加两个残基，其中29(2)为Cys，可满足β-domain新的结构要求。

关键词: 金属硫蛋白, 分子设计, 镉硫原子簇