大鼠正常肝脏和癌前病变肝脏微粒体谷胱甘肽 S-转移酶的纯化及其鉴定

Purificaton and Identification of Microsomal Glutathione S-Traesferases in Normal and Preneoplastic Rat Liver

本文通过 DE_(52)-纤维素和羟基磷灰石柱层析及 GSH-Sepharose-4B 亲和层析法,分离纯化了正常大鼠肝脏和癌前病变肝脏微粒体 GST,得到了三个微粒体 GST 同工酶组分,分别命名为A_1,A_2,A_3.用 SDS 聚丙烯酰胺凝胶电泳法测得其亚基分子量分别为25000D,26000D,43000D.以 CDNB 为底物按 Habig 方法测定 GST 活性,发现大鼠肝脏癌前病变微粒体同工酶 A_1和 A_2的活性显著增高,而同工酶 A_3在正常和癌前病变大鼠之间无显著差异.本实验结果表明,大鼠肝脏癌前病变组织的微粒体 GST 同工酶组分中 A_1和 A_2显著增高,可作为肝脏癌前病变的酶学指标.

Normal glutathione S-transferase （GST） was purified from normal and hyperplastic nodule（HN） bearing rat liver by diethylaminoethyl cellulose and hydroxylapatite column chromatography followed by glutathione-Sepa- rose 4B affinity chromatography.Three isoenzymes of microsomal GST were separated and were named A1,A2 and A3,respectively.The subunit molecular weights of three isoenzymes of microsomal GST determined by the sodium dodecyl sulfate polyacrylamide gel electrophoresis were 25kD, 26kD,and 43kD,respectively.Microsomal GST activities towards 1-chloro- 2,4-dinitrobenzene were determined by Habig’s method.It was found that the activities of isoenzyme A1 and A2 of microsomal GST in preneoplas- tic rat liver were markedly increased while As was changed a little in normal rat liver.The results indicate that microsomal GST isoenzyme A1 and A2 can be used as a preneoplastic hepatic marker enzyme.