Expression of mouse metallothionein-I cDNA in E.coli

摘要

Metallothioneins (MT) are a family of cysteine-rich, low molecular weightm metal-binding proteins [1]. They play an important role in the homeostasis of essential metal ions, e.g., zinc and copper [2], as well as in the detoxification of heavy metals such as cadimum and mercury. They are also important in mammalian UV response. MTs are usually single-chain proteins, without a alpha -helix or beta -sheet, and bind a total of 7 equivalents of bivalent metal ions. In this regard, MTs are ideal proteins for hte examination of structure/function relationships by site-directed mutagenesis or other molecular biological methods. The expression of MT in E.coli has been reported previously, but attempts to produce high levels of recombinatn proteins had only limited success because of their low stability [3,4]. We describe here the expression in E.Coli of mouse MT-I cDNA as a carboxyl-terminal extension of glutathione-S-transferase.