Cherian M G
J Nutr. 1977 Jun;107(6):965-72. doi: 10.1093/jn/107.6.965.
The objectives of this investigation were to study the role of zinc-thionein in the metabolism of excessive amounts of zinc and the re-utilization of zinc bound to this protein. Rats were injected ip with 5 mg Zn/kg body weight as zinc chloride for 5 days to induce the synthesis of zinc-thionein. Proteins with molecular weight of 10,000 with high affinity for zinc were synthesized in rat liver and intestine. These proteins were heat stable. Large scale isolation of this protein from rat liver was achieved by a simple method consisting of a heating step and sephadex gel fractionation. Intravenous injection of isolated 65Zn-thionein to rats resulted in similar organ distribution of zinc as that after 65ZnCL2 injection. Gel filtration experiments with liver supernatant from rats injected with 65Zn-thionein showed that a major portion of 65Zn was transfered to other protein fractions and was re-ultilized similar to inorganic salts of zinc. Morphological studies showed no toxic effects after injection of zinc-thionein. These results show that zinc-thionein is metabolically active and non-toxic.
本研究的目的是探讨锌硫蛋白在过量锌代谢及与该蛋白结合的锌的再利用中的作用。给大鼠腹腔注射5mg Zn/kg体重的氯化锌，连续5天，以诱导锌硫蛋白的合成。在大鼠肝脏和肠道中合成了分子量为10000且对锌具有高亲和力的蛋白质。这些蛋白质对热稳定。通过一个简单的方法，包括加热步骤和葡聚糖凝胶分级分离，从大鼠肝脏中大规模分离出这种蛋白质。给大鼠静脉注射分离得到的65Zn-硫蛋白后，锌在器官中的分布与注射65ZnCl2后的情况相似。对注射了65Zn-硫蛋白的大鼠肝脏上清液进行凝胶过滤实验表明，大部分65Zn转移到了其他蛋白质组分中，并像锌的无机盐一样被再次利用。形态学研究表明，注射锌硫蛋白后没有毒性作用。这些结果表明，锌硫蛋白具有代谢活性且无毒。
