大鼠正常肝、肝癌前病变组织谷胱甘肽S-转移酶的纯化及部分性质的研究

Purification and Properties Comparative Studies of Normal Rat Liver GST_S and Hyperplastic Nodles Bearing Rat Liver GST_S

本文用S-己基谷胱甘肽-琼脂糖-6B亲和层析一步纯化法分别获得电泳纯大鼠正常肝GST_S及含增生结节大鼠肝GST_S。经DE_(52)阴离子交換柱将含增生结节大鼠肝GST_S分离为三个同功酶组份,依次命名为C_(DE)A1及A2,C_(DE)占上柱总GST_S活性84.8％。等电聚焦电泳测定等电点分别为7.8、6.7及6.3。经CM_(52)阳离子交換柱获得五个同功酶组份,依次命名为A_(CM),C1,C2,C3及C4,等电点分别为7.8,7.4,7.9,8.3及8.6。A_(CM)的活性占CM_(52)柱上柱总活性的10％。SDS-PAGE电泳结果和正常大鼠肝GST_S比较,含增生结节大鼠肝GST_S同样出现Ya,Yb及Yc三条区带,而后者的氨基酸组成也与正常大鼠肝GST_S相近,但是和大鼠正常肝组织比较后者GST_S活性明显升高,以阳离子同工酶的活性为主。

In rat liver glutathione S-transferases(GST_S EC.2.5.1.18) are a group of isoenzymes playing many importan^+ roles. GST_S of normal rat liver and hyperplastic nodles bearing rat liver have been purified to homogenity by S-hexylglutathione affinity chromatography. In DE_(52) chromatography hyperplastic nodles bearing rat liver GST_S was separated to three isoenzymes named as C_(DE), A1, A2 in turn, PI of them measured by isoelectric focusing electrophoresis are 7.8, 6.7 and 6.3 respectively. In CM_(52) chromatography hyperplastic nodles bearing rat liver GST_S was separated to five isoenzymes named as A_(CM),C1,C2,C3,and C4 in turn,PI of them measured by isoelectric focus ing electrophoresis are 7.8, 7 4, 7.9, 8.3, and 8.6 respectively. The activity of A_(CM) is 10％ of total activity to the GM_(52) column.The activity of C3 aud C4 is 70％ of the total activity to the CM_(52) column.In SDS-PAGE, compared with normal rat liver GST_S,hyperplastic nodles bearing rat liver also show Ya, Yb and Yc band. Amino acid composition of hyperplastic nodles bea-ring rat liver GST_S is similar to that of normal rat liver GST_S. The activity of hy-perplastie nodles bearing rat liver GST_S is much higher than that of the normal rat liver, which is mainly attributable to the cationic isoenzymes.