Oshino R, Kamei K, Nishioka M, Shin M
Laboratory of Biochemistry, Kobe Yamate Women's Junior College, Hyogo.
J Biochem. 1990 Jan;107(1):105-10. doi: 10.1093/oxfordjournals.jbchem.a122991.
Four types of glutathione S-transferase were purified to homogeneity from guinea pig liver by DEAE-cellulose, Sephadex G-75, CM-cellulose, and affinity chromatography. These isozymes were named a, b, c, and d based on the reverse order of elution from a CM-cellulose column, and had specific activities of 89.6, 92.2, 99.0, and 44.0 units/mg, respectively, when assayed with 1 mM each of 1-chloro-2,4-dinitrobenzene and reduced glutathione. All four transferases of guinea pig liver were homodimers. The transferases b, c, and d had a similar molecular weight of 50,000 and their subunit sizes were 25,000, but the corresponding values for transferase a were 45,000 and 23,500, respectively. Transferase a was notably different in the activities towards organic hydroperoxides and 1,2-dichloro-4-nitrobenzene from the other isozymes. Transferases a and b, the major forms in guinea pig liver, were studied with respect to their biochemical properties, including kinetic parameters, absorption and fluorescence spectra, and bilirubin binding. Glutathione peroxidase activity of the transferase a was about 100 times higher than that of other isozymes. In guinea pig liver, it is estimated that transferase a is the major glutathione peroxidase, accounting for about 75% of the total organic hydroperoxide reduction.
通过DEAE - 纤维素、葡聚糖凝胶G - 75、CM - 纤维素和亲和层析从豚鼠肝脏中纯化出四种谷胱甘肽S - 转移酶，使其达到均一状态。这些同工酶根据从CM - 纤维素柱上洗脱的相反顺序命名为a、b、c和d，当用1 mM的1 - 氯 - 2,4 - 二硝基苯和还原型谷胱甘肽分别进行测定时，它们的比活性分别为89.6、92.2、99.0和44.0单位/毫克。豚鼠肝脏的所有四种转移酶均为同二聚体。转移酶b、c和d的分子量相似，为50,000，其亚基大小为25,000，但转移酶a的相应值分别为45,000和23,500。转移酶a在对有机氢过氧化物和1,2 - 二氯 - 4 - 硝基苯的活性方面与其他同工酶明显不同。对豚鼠肝脏中的主要形式转移酶a和b进行了生化特性研究，包括动力学参数、吸收光谱和荧光光谱以及胆红素结合。转移酶a的谷胱甘肽过氧化物酶活性比其他同工酶高约100倍。在豚鼠肝脏中，估计转移酶a是主要的谷胱甘肽过氧化物酶，约占总有机氢过氧化物还原量的75%。
