Interrelationship between anionic and cationic forms of glutathione S-transferases of human liver.
Interrelationship between anionic and cationic forms of glutathione S-transferases of human liver.
复制标题
人肝脏谷胱甘肽 S-转移酶阴离子和阳离子形式之间的相互关系。
DOI：
10.1042/bj1910001
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发表时间：
1980
期刊：
影响因子：
--
通讯作者：
Saneto,RP
中科院分区：
文献类型：
--
作者：
Awasthi,YC;Dao,DD;Saneto,RP
人肝脏谷胱甘肽 S-转移酶（GSH S-转移酶）被分为阳离子和阴离子蛋白质。在 (NH4)2SO4 分级过程中，阴离子 GSH S-转移酶集中在 65% 饱和的 (NH4)2SO4 级分中，而阳离子 GSH S-转移酶则在 80% 饱和的 (NH4)2SO4 级分中分离。通过使用 DEAE-纤维素上的离子交换色谱法、Sephadex G-200 凝胶过滤、结合环氧活化琼脂糖的 GSH 亲和色谱法和等电聚焦，从 65% 饱和的 (NH4)2SO4 级分中，将两种新的阴离子 GSH S-转移酶 omega 和 psi 纯化至同质。通过类似的程序，从 80% 饱和的 (NH4)2SO4 级分中纯化出阳离子 GSH S-转移酶。 GSH S-转移酶 omega 和 psi 的等电点分别为 4.6 和 5.4。 GSH S-转移酶 omega 是人肝脏中主要的阴离子 GSH S-转移酶，而 GSH S-转移酶 psi 仅存在微量。亚基摩尔重量GSH S-转移酶 omega 的分子量约为 22500，而阳离子 GSH S-转移酶 omega 的分子量约为 24500。描述了 GSH S-转移酶 omega 的动力学和结构特性以及氨基酸组成。针对阳离子 GSH S-转移酶产生的抗体与 GSH S-转移酶 omega 发生交叉反应。 GSH S-转移酶 omega 和阳离子 GSH S-转移酶的催化特性存在显着差异。所有五种阳离子 GSH S-转移酶均显示 GSH 过氧化物酶 II 活性，而两种阴离子 GSH S-转移酶均不显示此活性。
Human liver glutathione S-transferases (GSH S-transferases) were fractionated into cationic and anionic proteins. During fractionation with (NH4)2SO4 the anionic GSH S-transferases are concentrated in the 65%-saturated-(NH4)2SO4 fraction, whereas the cationic GSH S-transferases separate in the 80%-saturated-(NH4)2SO4 fraction. From the 65%-saturated-(NH4)2SO4 fraction two new anionic GSH S-transferases, omega and psi, were purified to homogeneity by using ion-exchange chromatography on DEAE-cellulose, Sephadex G-200 gel filtration, affinity chromatography on GSH bound to epoxy-activated Sepharose and isoelectric focusing. By a similar procedure, cationic GSH S-transferases were purified from the 80%-saturated-(NH4)2SO4 fraction. Isoelectric points of GSH S-transferases omega and psi are 4.6 and 5.4 respectively. GSH S-transferase omega is the major anionic GSH S-transferase of human liver, whereas GSH S-transferase psi is present only in traces. The subunit mol.wt. of GSH S-transferase omega is about 22500, whereas that of cationic GSH S-transferases is about 24500. Kinetic and structural properties as well as the amino acid composition of GSH S-transferase omega are described. The antibodies raised against cationic GSH S-transferases cross-react with GSH S-transferase omega. There are significant differences between the catalytic properties of GSH S-transferase omega and the cationic GSH S-transferases. GSH peroxidase II activity is displayed by all five cationic GSH S-transferases, whereas both anionic GSH S-transferases do not display this activity.