Metal binding ability of metallothionein-3 expressed in Escherichia coli.
Metal binding ability of metallothionein-3 expressed in Escherichia coli.
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DOI：
10.1111/j.1742-7843.2005.pto960404.x
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发表时间：
2005-04
影响因子：
3.1
通讯作者：
Shigeru Toriumi;T. Saito;T. Hosokawa;Yasumitsu Takahashi;T. Numata;M. Kurasaki
中科院分区：
文献类型：
--
作者：
Shigeru Toriumi;T. Saito;T. Hosokawa;Yasumitsu Takahashi;T. Numata;M. Kurasaki
金属硫蛋白-3/生长抑制因子是金属硫蛋白基因家族的脑特异性成员，并且损害培养的神经元的存活和轴突形成。金属硫蛋白-3与其它金属硫蛋白家族一样，可以与重金属如Zn、Cu或Cd结合。然而，其作为生长抑制因子的生物学功能明显区别于其他金属硫蛋白。为了更好地了解金属硫蛋白-3的生长抑制活性与金属硫蛋白-3结合的金属之间的关系，将金属硫蛋白-3与金属硫蛋白-1和-2的金属结合能力进行比较分析。通过pH滴定和5-5'-二硫代双（2-硝基苯甲酸）分析，比较了金属硫蛋白3与金属的结合能力。金属离子对金属硫蛋白-3的亲和力大小为Cu>Cd>Zn，与金属硫蛋白-1和-2的亲和力大小相同。然而，金属硫蛋白-3对Cu的亲和力远高于金属硫蛋白-1和-2。金属硫蛋白3与铜的强亲和力可能与其生长抑制活性有关。
Metallothionein-3/growth inhibitory factor is a brain-specific member of the metallothionein gene family, and impairs the survival and neurite formation of cultured neurons. Metallothionein-3 can bind heavy metals such as Zn, Cu, or Cd almost in the same way as other metallothionein family. However, its biological function as growth inhibitory factor apparently distinguishes metallothionein-3 from other metallothioneins. To better understanding of the relationship between the growth inhibitory activity of metallothionein-3 and metals bound to metallothionein-3, the metal-binding ability of metallothionein-3 was analyzed in comparison with those of metallothionein-1 and -2. The metal-binding ability of metallothionein-3 was evaluated by pH titration and 5-5' dithiobis (2-nitrobenzoic) acid (DTNB) analysis as compared with those of the other metallothioneins. The affinity of metal ions for metallothionein-3 was indicated as follows, Cu>Cd>Zn, same as metallothionein-1 and -2. However, the affinity of metallothionein-3 to Cu was much higher than that of metallothionein-1 and -2. The strong affinity to Cu of metallothionein-3 might be related to its growth inhibitory activity.