硒蛋白R——一个独特的甲硫氨酸亚砜还原酶

Selenoprotein R: A Unique Methionine Sulfoxide Reductase

硒蛋白是一类以硒代半胱氨酸为活性中心的蛋白质,利用硒氢基的强还原性,硒蛋白在生物体内发挥重要的抗氧化功能。目前发现,人类基因组中有25种硒蛋白的编码基因,其中硒蛋白R是唯一一个含有硒代半胱氨酸的甲硫氨酸亚砜还原酶,它位于细胞质及细胞核中,由于其空间结构和硒元素的强亲核性,硒蛋白R能特异性还原R型甲硫氨酸亚砜中被氧化的硫元素。硒蛋白R能够与肌动蛋白、瞬时电位通道蛋白及β-淀粉样蛋白等多种蛋白质相互作用,可能在中枢神经系统中具有重要的功能,并与神经退行性疾病的发生发展具有密切关系。

Selenoproteins represent a category of proteins that possess selenocysteine as the active center, by taking advantage of robust reducing ability of selenium, selenoproteins exert an important antioxidant function in various organisms. To date, there are 25 genes that encode selenoproteins found in human genome. Among them, selenoprotein R is the only methionine sulfoxide reductase that contains selenocysteine. It is located in the cytoplasm and nucleus, given the protein structure and strong nucleophilicity of selenium, selenoprotein R is competent to specifically reduce the oxidized sulfur in methionine-R-sulfoxide. Selenoprotein R could directly interact with many proteins, such as actin, transient receptor potential channel proteins, and [3-amyloid protein. It may play crucial roles in the central nervous system and is closely related with the development of neurodegenerative diseases.