脑特异性金属硫蛋白Ⅲ研究进展

Research Progress in Brain Specific Metallothionein Ⅲ

金属硫蛋白Ⅲ（ＭＴⅢ）是富含半胱氨酸的低分子量蛋白，主要在脑内含Ｚｎ２＋神经元表达，与脑的发育过程有关。ＭＴⅢ可抑制体外培养的神经细胞生长和存活。ＭＴⅢ与Ｚｎ２＋的结合有相对特异性，可能影响依赖于Ｚｎ２＋的一系列生物活动。ＡＤ患者脑内ＭＴⅢ表达减少，敲除ＭＴⅢ基因的小鼠对红藻氨酸诱发癫痫更敏感。

Metallothionein Ⅲ(MT Ⅲ) is a low molecular weight protein characterized by its abundant content of cysteins. It is predominantly expressed in the zinc containing neurons and associated with the development of brain. MT Ⅲ inhibits the survival and neurite formation of the cultured neurons in vitro. It has comparatively specific affinity for zinc, thus may regulate the zinc dependent biological processes. Studies demonstrating that MT Ⅲ is down regulated in Alzheimer's disease and that MT Ⅲ “knockout” mice appear highly sensitive to kainate induced seizures suggest that it may play important roles in some degenerative diseases of the brain.