Purification and characterization of methionine sulfoxide reductases from mouse and Staphylococcus aureus and their substrate stereospecificity
Purification and characterization of methionine sulfoxide reductases from mouse and Staphylococcus aureus and their substrate stereospecificity
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DOI：
10.1006/bbrc.2001.6171
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发表时间：
2002-01-11
影响因子：
3.1
通讯作者：
Stadtman, ER
中科院分区：
文献类型：
--
作者：
Moskovitz, J;Singh, VK;Stadtman, ER
许多生物已被证明具有蛋氨酸亚砜还原酶（MsrA），具有将S形式的游离和蛋白质结合的蛋氨酸亚砜还原为蛋氨酸的高特异性。最近，在几种生物体中发现了一种不同形式的还原酶（称为MsrB）。我们在这里表明MsrB是一种硒蛋白，对自由和蛋白质结合的蛋氨酸亚砜的R形式的还原表现出高特异性。该酶从小鼠肝脏中部分纯化，制备了小鼠MsrB基因的衍生物，其中指定硒代半胱氨酸结合的密码子被半胱氨酸密码子取代，并在大肠杆菌中过表达。将改性后的MsrB蛋白与MsrA蛋白的性质进行了直接比较。此外，我们已经证明，在金黄色葡萄球菌中有两个MsrA和一个非硒蛋白MsrB，其表现出与小鼠MsrB相同的底物立体特异性。
Many organisms have been shown to possess a methionine sulfoxide reductase (MsrA), exhibiting high specificity for reduction the S form of free and protein-bound methionine sulfoxide to methionine. Recently, a different form of the reductase (referred to as MsrB) has been detected in several organisms. We show here that MsrB is a selenoprotein that exhibits high specificity for reduction of the R forms of free and protein-bound methionine sulfoxide. The enzyme was partially purified from mouse liver and a derivative of the mouse MsrB gene, in which the codon specifying selenocystein incorporation was replaced by the cystein codon, was prepared, cloned, and overexpressed in Escherichia coli. The properties of the modified MsrB protein were compared directly with those of MsrA. Also, we have shown that in Staphylococcus aureus there are two MsrA and one nonselenoprotein MsrB, which demonstrates the same substrate stereospecificity as the mouse MsrB.