Mozer T J, Tiemeier D C, Jaworski E G
Biochemistry. 1983 Mar 1;22(5):1068-72. doi: 10.1021/bi00274a011.
Two glutathione S-transferase (GST) activities have been identified and purified from etiolated corn tissue. The first, designated GST I enzyme, is constitutively present in corn tissue, and the second, designated GST II enzyme, is present only in tissue which has been treated with chemical antidotes which protect corn against chloroacetanilide herbicides. The total activity constitutes approximately 2% of the soluble protein in these tissues. The native forms of these enzymes have molecular weights of approximately 50 000 as determined by Sephadex G-100 chromatography. On sodium dodecyl sulfate-polyacrylamide gels, GST I enzyme migrates primarily as a single band of molecular weight 29 000, and GST II enzyme migrates as primarily two bands of molecular weight 29 000 and 27 000. Both enzymes catalyze the formation of a glutathione-herbicide conjugate in vitro when the herbicide alachlor is used as a substrate. This conjugation results in elimination of the biological activity of the herbicide.
已从黄化玉米组织中鉴定并纯化出两种谷胱甘肽S-转移酶（GST）活性。第一种，命名为GST I酶，在玉米组织中组成性存在；第二种，命名为GST II酶，仅存在于用化学解毒剂处理过的组织中，这些解毒剂可保护玉米免受氯乙酰胺类除草剂的侵害。这些组织中的总活性约占可溶性蛋白质的2%。通过葡聚糖G-100色谱法测定，这些酶的天然形式分子量约为50000。在十二烷基硫酸钠-聚丙烯酰胺凝胶上，GST I酶主要迁移为一条分子量为29000的单带，GST II酶主要迁移为两条分子量分别为29000和27000的带。当除草剂甲草胺用作底物时，两种酶在体外均催化谷胱甘肽-除草剂缀合物的形成。这种缀合导致除草剂生物活性的消除。
