Ramage P I, Nimmo I A
Comp Biochem Physiol B. 1984;78(1):189-94. doi: 10.1016/0305-0491(84)90166-4.
Chromatofocusing separated the glutathione S-transferases of trout liver cytosol into species termed cationic (eluted from pH 8-5) and anionic (eluted by 1.0 M NaCl at pH 5). The cationic enzymes were separated from cytosol by S-hexylglutathione affinity chromatography, ultrafiltration and chromatofocusing (pH 9-7) into 4 major (C1, C2, C4 and C5) and 3 minor fractions. The anionic material was not purified in this way because only 50% of the activity bound to the S-hexylglutathione column. The major cationic enzymes had similar half-saturation concentrations for GSH (0.2 mM) and 1-chloro-2,4-dinitrobenzene (0.4 mM); those of the anionic material were higher (0.7 mM, 1.9 mM respectively). The substrate specificities of the cationic enzymes C1 and C2 were similar (e.g., conjugation of bromosulphophthalein) as were those of C4 and C5 (e.g., conjugation of 1,2-epoxy-3-(p-nitrophenoxy) propane). The anionic material had a different specificity (e.g., rapid conjugation of p-nitrobenzyl chloride). SDS-polyacrylamide gel electrophoresis showed C1 and C2 to be homodimers of subunit Mr 22,400, C4 to be a heterodimer (Mr's 22,400 and 24,500), and C5 predominantly an Mr 22,400 homodimer.
色谱聚焦法将鳟鱼肝细胞质中的谷胱甘肽S-转移酶分离为阳离子型（在pH 8至5洗脱）和阴离子型（在pH 5用1.0 M氯化钠洗脱）。阳离子型酶通过S-己基谷胱甘肽亲和色谱、超滤和色谱聚焦法（pH 9至7）从细胞质中分离为4个主要组分（C1、C2、C4和C5）和3个次要组分。阴离子型物质未采用这种方法纯化，因为只有50%的活性与S-己基谷胱甘肽柱结合。主要的阳离子型酶对谷胱甘肽（0.2 mM）和1-氯-2,4-二硝基苯（0.4 mM）具有相似的半饱和浓度；阴离子型物质的半饱和浓度较高（分别为0.7 mM和1.9 mM）。阳离子型酶C1和C2的底物特异性相似（例如，溴磺酞钠的结合），C4和C5的底物特异性也相似（例如，1,2-环氧-3-(对硝基苯氧基)丙烷的结合）。阴离子型物质具有不同的特异性（例如，对硝基苄基氯的快速结合）。SDS-聚丙烯酰胺凝胶电泳显示C1和C2是亚基Mr 22,400的同二聚体，C4是异二聚体（Mr分别为22,400和24,500），C5主要是Mr 22,400的同二聚体。
