摘要
新生大鼠在腹腔注射^(203)Pb染毒后24小时处死,通过梯度离心,取脑匀浆的上清液,经SephadexG—200层析方法,得到含有两个显示^(203)Pb放射性的高峰,其中有两个峰的分子量均小于25000,进一步采用Fluphenazin—Sepharose—4B柱亲和层析,制备出显示^(203)Pb放射性的蛋白质,经SDS—PAGE分析鉴定,其蛋白质分子量为16800,与CaM分子量一致,此结果为证实Pb^(2+)在脑内与CaM相结合,并为CaM—Pb^(2+)结合物形式存在于脑神经细胞膜上提供了依据。
In this study .the newborn rats were injected 203Pb intra - peritoneally and killed after 24 hours of administration. The supernatant of brain homogenate was obtained with gradient centrifugation. There are two 203 Pb - labelled radioactive peaks of protein with molecular weight lower than 25000 on Sephadex G -200 chromatogram. 203Pb -labelled radioactive protein was prepared with Fluphenazin -Sepharose -4B affinity chromatography. Analysis of SDS-PAGE suggested that the molecular weight of the 203Pb-labelled radioactive protein was 16800 coincidential to that of calmodulin. Results indicated that Pb203 is combined with CaM in the form of CaM -Pb2+ presented on the membrane of neurons i1 the brain.
基金
国家自然科学基金
