Ahmad Rumana, Srivastava Arvind K
Division of Biochemistry, Central Drug Research Institute, Lucknow, 226001, India.
Parasitol Res. 2007 Feb;100(3):581-8. doi: 10.1007/s00436-006-0295-8. Epub 2006 Oct 6.
Glutathione (GSH) metabolism represents a potential target for antiparasitic drug design. Glutathione-S-transferase (GST), an important enzyme of the GSH cycle, is considered to be an essential detoxification enzyme in parasitic species. Soluble GST from rodent malarial parasites Plasmodium yoelii was purified to homogeneity using a combination of salt precipitation, affinity chromatography on GSH-sepharose 6B and ultrafiltration. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis revealed a single band and activity staining was also detected on PAGE gels. Kinetic studies on the purified enzyme revealed significant differences between the parasitic and mammalian enzymes. The purified enzyme exhibited an optimum pH of 8.2 and K (m) values of 0.2+/-0.213 and 3.3+/-0.056 mM with respect to co-substrate GSH and substrate 1-chloro-2, 4-dinitrobenzene (CDNB), respectively. Hemin, the known mammalian GST inhibitor was found to be a potent inhibitor of P. yoelii GST, with a K (i) of 4.0 microM.
谷胱甘肽（GSH）代谢是抗寄生虫药物设计的一个潜在靶点。谷胱甘肽 - S - 转移酶（GST）是GSH循环中的一种重要酶，被认为是寄生虫物种中一种必不可少的解毒酶。使用盐沉淀、GSH - 琼脂糖6B亲和色谱和超滤相结合的方法，将来自啮齿动物疟原虫约氏疟原虫的可溶性GST纯化至同质。十二烷基硫酸钠聚丙烯酰胺凝胶电泳（SDS - PAGE）分析显示有一条单一的条带，并且在PAGE凝胶上也检测到了活性染色。对纯化酶的动力学研究揭示了寄生虫酶和哺乳动物酶之间的显著差异。纯化后的酶表现出最适pH为8.2，相对于共底物GSH和底物1 - 氯 - 2,4 - 二硝基苯（CDNB）的K（m）值分别为0.2±0.213和3.3±0.056 mM。已知的哺乳动物GST抑制剂血红素被发现是约氏疟原虫GST的有效抑制剂，其K（i）为4.0 microM。
