【摘要】 Wistar雄性大鼠经腹腔注射CdCl₂诱导其肝脏合成金属硫蛋白。取鼠肝,先经匀浆、热变性、乙醇-氯仿萃取、丙酮沉淀等步骤,后由Sephadex G-75、DEAE-52柱层析,得金属硫蛋白的两亚型Ⅰ和Ⅱ。经原子吸收光谱测定每蛋白分子含有5个镉和2个锌。用枯草杆菌酶割法制备并分离了金属硫蛋白亚型Ⅱ的α结构域片段。还用NMR研究了金属硫蛋白的两个亚型及所得的α结构域片段。更多还原

【Abstract】 The rat liver metallothionein was induced by administering 7 subcutaneous injection of CdCl2 to the wistar rat. The purification protocal involved homogenization of rat liver, heating, extraction by ethanol-chloroform, acetone precipitation, and finally, chromatography on Sephadex G-75 and DEAE-52 columns. Two isoforms of metallothionein, Cd5Zn2-MT- Ⅰ and -Ⅱ , with A250/ A250> 20 were obtained. MT- Ⅱα domain fragment containing four cadmium ions was also isolated by digestion with subtilysin. 1H NMR spectra of MT- Ⅰ , - Ⅱ were in agreement with those reported in literatures. The spectrum of MT- Ⅰ α domain shows that there is no existence of β fragment in this preparation.更多还原