PURIFICATION OF Cd-BINDING PROTEIN FROM MAIZE ROOTS BY REVERSE-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

An efficient procedure of purification of Cd-binding protein in roots of maize has been established. Young seedlings of maize were exposed to a medium containing CdCl2 to induce the production of Cd-binding protein in their roots. The protein was purified after heat treatment by ion-exchange chromatography and reverse-phase HPLC. The resulting protein was identified as a purified product by N-terminal amino acid with the dansyl method. Its molecular weight was 3200 dalton, the cysteine content was 29.5%, about 3 Cd atoms were bound to one molecule of the protein and the Cd : cystine ratio was 1 : 2.3. According to its character, this protein could be a kind of plant metallothionein-like protein.     

用HpLC反相柱层析纯化玉米根镉结合蛋白

本研究建立了纯化玉米根镉结合蛋白的有效方法.其步骤为用加热处理由CdCl_2诱导形成的玉米根的粗提物,经过离子交换柱层析后的Cd结合复合物,连续用HpLC反相柱层析,获得了纯的蛋白.该蛋白质的分子量为3200D;半胱氨酸含量为29.6％;每个蛋白质分子结合大约3个Cd原子;Cd与半胱氨酸的比值为1:2.3.根据其特性说明它可能是植物类金属硫蛋白.