Ebadi M, Swanson S
Department of Parmacology, University of Nebraska College of Medicine, Omaha 68105.
Experientia Suppl. 1987;52:289-91. doi: 10.1007/978-3-0348-6784-9_24.
A metallothionein-like protein has been identified recently in the rat brain which resembles in some but not all aspects a hepatic metallothionein. The synthesis of this protein is stimulated following the administration of zinc and copper but not cadmium. The zinc-stimulated protein incorporates 35S cysteine 24-fold higher than the native, unstimulated protein; is blocked by actinomycin D; produces two isoforms by ion exchange chromatography on DEAE Sephadex A 25 columns; and, by high performance liquid chromatography, depicts a similar but not identical profile to zinc-stimulated hepatic metallothionein. Preliminary studies have shown that the metallothionein-like protein isoform I possesses a Mr of 6200 and consists of 60 residues with 12 cysteine and no histidine, arginine, leucine, tyrosine, or phenylalanine. Since the synthesis of this protein is reduced in the brains of zinc-deficient rats, it is postulated that the free pool of zinc may serve as one of the factors that regulates the synthesis of this protein.
最近在大鼠脑中发现了一种类金属硫蛋白，它在某些方面但并非所有方面都类似于肝脏金属硫蛋白。给予锌和铜后会刺激这种蛋白质的合成，但镉不会。锌刺激的蛋白质掺入35S半胱氨酸的量比天然未刺激的蛋白质高24倍；被放线菌素D阻断；通过在DEAE Sephadex A 25柱上进行离子交换色谱产生两种同工型；并且通过高效液相色谱法，显示出与锌刺激的肝脏金属硫蛋白相似但不完全相同的图谱。初步研究表明，类金属硫蛋白同工型I的分子量为6200，由60个残基组成，有12个半胱氨酸，没有组氨酸、精氨酸、亮氨酸、酪氨酸或苯丙氨酸。由于缺锌大鼠脑中这种蛋白质的合成减少，推测锌的自由池可能是调节这种蛋白质合成的因素之一。
