Yamamura M, Suzuki K T
Comp Biochem Physiol C Comp Pharmacol Toxicol. 1984;79(1):63-9.
A relatively high concentration of metallothionein was present in the liver of the control mature tortoise Clemmys mutica. The administrations of cadmium and copper to Clemmys mutica increased the metals in the liver with concomitant decrease of zinc, which was due to substitution of zinc in the native metallothionein with cadmium and copper. The Clemmys metallothionein was a mixture of three isoproteins which were abundant in half-cystine (34.2-34.6 mol%) and lysine (10.8-11.9 mol%), but lacked aromatic amino acids. One of the isoproteins, MT-I, contained one residue of histidine, which was an identical feature with frog and avian metallothioneins.
在对照成年日本水龟（Clemmys mutica）的肝脏中存在相对较高浓度的金属硫蛋白。给日本水龟施用镉和铜会使肝脏中的金属含量增加，同时锌含量降低，这是由于镉和铜取代了天然金属硫蛋白中的锌。日本水龟金属硫蛋白是三种同型蛋白的混合物，半胱氨酸（34.2 - 34.6摩尔%）和赖氨酸（10.8 - 11.9摩尔%）含量丰富，但缺乏芳香族氨基酸。其中一种同型蛋白MT - I含有一个组氨酸残基，这与青蛙和鸟类的金属硫蛋白具有相同特征。
