Reddy C C, Li N, Tu C P
Biochem Biophys Res Commun. 1984 Jun 29;121(3):1014-20. doi: 10.1016/0006-291x(84)90778-2.
A new glutathione S-transferase has been purified to homogeneity from 105,000 X g supernatant of Sprague-Dawley rat liver homogenates. The purified enzyme exhibited specific activities of approximately 1.8, and 0.12 mumoles X min-1 X mg-1 toward 1-chloro 2,4-dinitrobenzene and cumene hydroperoxide respectively. The SDS gel electrophoresis data on subunit composition revealed that the new transferase is composed of two subunits with an identical Mr of 24,400 (Y alpha Family). Our in vitro translation experiments with rat liver poly(A) RNAs and substrate specificity data suggest that this subunit is different from the previously reported Ya , Yb and Yc subunits of rat liver glutathione S-transferases. Comparatively, the new isozyme showed significant activity toward 1,2 epoxy-3-(P-nitrophenoxy)-propane, ethacrynic acid and P-nitrophenyl acetate, 0.4, 0.34 and 0.18 mumoles. min-1 X mg-1 respectively.
一种新的谷胱甘肽S-转移酶已从斯普拉格-道利大鼠肝脏匀浆的105,000×g上清液中纯化至同质。纯化后的酶对1-氯-2,4-二硝基苯和氢过氧化异丙苯的比活性分别约为1.8和0.12微摩尔·分钟⁻¹·毫克⁻¹。关于亚基组成的SDS凝胶电泳数据显示，新的转移酶由两个亚基组成，其相同的相对分子质量为24,400（Yα家族）。我们用大鼠肝脏多聚腺苷酸RNA进行的体外翻译实验和底物特异性数据表明，该亚基与先前报道的大鼠肝脏谷胱甘肽S-转移酶的Ya、Yb和Yc亚基不同。相比之下，新的同工酶对1,2-环氧-3-(对硝基苯氧基)-丙烷、依他尼酸和对硝基苯乙酸表现出显著活性，分别为0.4、0.34和0.18微摩尔·分钟⁻¹·毫克⁻¹。
