METHIONINE SULFOXIDE REDUCTASES

蛋白质中的蛋氨酸可能会受到不可避免的反应性攻击 作为电子传输过程的副产品产生的氧物种 在细胞内，形成蛋氨酸亚砜。一种酶，蛋氨酸 亚砜还原酶，可以逆转这种氧化。一种有效成分测定方法的研究 还原酶已被修饰和调整，以测量在 取自不同年龄动物的大鼠肝脏匀浆。结果发现， 还原酶的比活性逐渐下降，从而使水平 24个月的人大约是两个月的人的80% 费舍尔344只老鼠。这一观察结果与早先的 以甲孕酮为底物的羰基还原酶。还原酶有 是从大肠杆菌中提纯的

Methionine in proteins may be subject to attack by unavoidable reactive oxygen species produced as side products of electron transport process in the cell, forming methionine sulfoxide. An enzyme, methionine sulfoxide reductase, can reverse this oxidation. A method of assay of the reductase has been modified and adapted to measure the activity in rat liver homogenates from animals of various ages. It was found that the specific activity of the reductase gradually dropped so that levels at 24 months were about 80 percent of those found at two months in Fisher 344 rats. This observation parallels that made earlier for carbonyl reductase using metyrapone as substrate. The reductase has been purified from Escherichia coli