Metal-induced formation of metallothionein in rat liver.
Metal-induced formation of metallothionein in rat liver.
复制标题
金属诱导大鼠肝脏中金属硫蛋白的形成。
DOI：
10.1016/0003-9861(75)90115-0
复制
发表时间：
1975
影响因子：
3.9
通讯作者：
K. Rajagopalan
中科院分区：
文献类型：
--
作者：
D. Winge;R. Premakumar;K. Rajagopalan
金属硫蛋白，它积累在大鼠的肝脏已收到皮下注射镉，已被纯化到均匀的使用葡聚糖凝胶色谱，丙酮分馏和色谱上的二乙基氨基乙基（DEAE）-纤维素。阴离子交换色谱法的镉-硫蛋白产生两种组分不同的氨基酸组成。这两种形式的纯化镉硫蛋白显示这样的特点，如高半胱氨酸含量和缺乏芳香族氨基酸。分子量为10，200，每个蛋白质分子的典型金属含量为5个镉原子和2个锌原子，这是两种形式的共同特征。在暴露于锌、汞或银的大鼠中诱导的低分子量蛋白质已通过与用于Cd-硫蛋白的相同程序纯化。在每种情况下，硫蛋白在DEAE-纤维素上都被分解成似乎相同的两个部分。在聚丙烯酰胺凝胶电泳上，两种金属蛋白的迁移率与相应的Cd-硫蛋白相同，而Hg-硫蛋白和Zn-硫蛋白的氨基酸组成与相应的Cd-硫蛋白非常相似。因此，在大鼠中由锌、汞和银诱导的蛋白质与先前已知的由镉诱导的金属硫蛋白的同一性已经确立。
Metallothionein, which accumulates in livers of rats which have received subcutaneous injections of cadmium, has been purified to homogeneity by the use of Sephadex chromatography, acetone fractionation and chromatography on diethyl aminoethyl (DEAE)-cellulose. Anion exchange chromatography of Cd-thionein yielded two components differing in amino acid composition. Both forms of purified Cd-thionein displayed such characteristic features as high cysteine content and lack of aromatic amino acids. A molecular weight of 10,200 and a typical metal content of five atoms of cadmium and two atoms of zinc per protein molecule were common features of the two forms.The low molecular weight proteins which are induced in rats exposed to zinc, mercury or silver have been purified by the same procedure as was used for Cd-thionein. In each case the thionein was resolved into what appeared to be the same two fractions on DEAE-cellulose. The two forms of each metalloprotein exhibited mobilities identical to those of the corresponding Cd-thionein on polyacrylamide-gel electrophoresis.The amino acid compositions of the more anionic forms of Hg-thionein and Zn-thionein were quite similar to that of the corresponding Cd-thionein. Thus, the identity of the proteins induced in rats by zinc, mercury and silver with the previously known metallothionein induced by cadmium has been established.