Hiratsuka A, Okada T, Nishiyama T, Fujikawa M, Ogura K, Okuda H, Watabe T, Watabe T
Department of Drug Metabolism and Molecular Toxicology, Tokyo College of Pharmacy, Japan.
Biochem Biophys Res Commun. 1994 Jul 15;202(1):278-84. doi: 10.1006/bbrc.1994.1924.
Two novel theta class glutathione S-transferases (GSTs), designated Yrs-Yrs' and Yrs'-Yrs', were isolated from rat liver cytosol and purified to homogeneity. Polyclonal antibody raised against the previously reported theta class GST Yrs-Yrs (Hiratsuka, A. et al., J. Biol. Chem. 265, 11973 (1990)) cross-reacted with GSTs Yrs-Yrs' and Yrs'-Yrs'. These three theta class GSTs had different pI values and were separated by chromatofocusing. The enzyme subunit Yrs' was separated from Yrs by reverse partition HPLC, but identical to Yrs in the first 37 N-terminal amino acid sequence. Like GST Yrs-Yrs, both GSTs Yrs-Yrs' and Yrs'-Yrs' were not retained on an S-hexyl-GSH affinity column and had little activity toward 1-chloro-2,4-dinitrobenzene. However, they showed potent activities toward the reactive sulfate ester of the carcinogen, 5-hydroxymethylchrysene. GSTs Yrs-Yrs and Yrs'-Yrs' showed much higher GSH peroxidase activities toward arachidonate hydroperoxide than did rat liver alpha class GST Ya-Ya.
从大鼠肝脏胞液中分离出两种新型的θ类谷胱甘肽S-转移酶（GSTs），分别命名为Yrs-Yrs'和Yrs'-Yrs'，并纯化至同质。针对先前报道的θ类GST Yrs-Yrs制备的多克隆抗体（Hiratsuka, A.等人，《生物化学杂志》265, 11973 (1990)）与GSTs Yrs-Yrs'和Yrs'-Yrs'发生交叉反应。这三种θ类GSTs具有不同的pI值，通过色谱聚焦法分离。酶亚基Yrs'通过反向分配高效液相色谱法与Yrs分离，但在前37个N端氨基酸序列上与Yrs相同。与GST Yrs-Yrs一样，GSTs Yrs-Yrs'和Yrs'-Yrs'都不能保留在S-己基-GSH亲和柱上，对1-氯-2,4-二硝基苯的活性很低。然而，它们对致癌物5-羟甲基屈的活性硫酸酯表现出很强的活性。与大鼠肝脏α类GST Ya-Ya相比，GSTs Yrs-Yrs和Yrs'-Yrs'对花生四烯酸氢过氧化物表现出更高的谷胱甘肽过氧化物酶活性。
