Stimulation of a human erythrocyte membrane ATPase by glutathione conjugates.
Stimulation of a human erythrocyte membrane ATPase by glutathione conjugates.
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谷胱甘肽结合物刺激人红细胞膜 ATP 酶。
DOI：
10.1016/0041-008x(90)90164-p
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发表时间：
1990
影响因子：
3.8
通讯作者：
Awasthi,YC
中科院分区：
文献类型：
--
作者：
Sharma,R;Gupta,S;Ahmad,H;Ansari,GA;Awasthi,YC
S-(2,4-二硝基苯基) 谷胱甘肽 (Dnp-SG) 的 ATP 依赖性转运过程由一种名为 Dnp-SG ATPase 的新型 ATP 酶介导，已在人红细胞中得到证实（LaBelle 等人，FEBS Lett.228, 51–53, 1988）。为了研究 Dnp-SG ATP 酶系统是否代表了谷胱甘肽 (GSH) 异生物质缀合物转运的通用机制，在由人红细胞制备的膜囊泡中研究了不同 GSH 缀合物对该 ATP 酶的刺激。几种 GSH 缀合物的动力学参数，包括 S-（甲基）谷胱甘肽、S-（正丙基）谷胱甘肽、S-（正戊基）谷胱甘肽、S-（正癸基）谷胱甘肽、S-（对氯苯甲酰基）谷胱甘肽、S-（对硝基苄基）谷胱甘肽和 GSH 缀合物 测定 9,10-环氧硬脂酸以评估其对 Dnp-SG ATP 酶的亲和力。这些研究表明，所有这些缀合物都会刺激人红细胞膜的 Dnp-SG ATP 酶。发现不同缀合物的 Dnp-SG ATPase 的表观 Km 值在 0.26-0.66 mm 范围内，Vmax 值范围在 0.55 至 4.44 nmol/min/mg 蛋白质之间。这些研究的结果表明，红细胞膜 Dnp-SG ATP 酶代表了转运由外源物质以及内源产生的亲电子化合物（例如环氧硬脂酸）形成的 GSH 缀合物的通用机制。这表明Dnp-SG ATP酶与GSH和GSH S-转移酶结合可能在保护红细胞免受外源性和内源性亲电子毒物的影响中发挥重要作用。
An ATP-dependent transport process for S-(2,4-dinitrophenyl) glutathione (Dnp-SG) mediated by a novel ATPase designated as Dnp-SG ATPase has been demonstrated in human erythrocytes (LaBelle et al., FEBS Lett.228, 51–53, 1988). In order to investigate whether the Dnp-SG ATPase system represents a generalized mechanism for the transport of xenobiotic conjugates of glutathione (GSH), stimulation of this ATPase by different GSH conjugates was studied in membrane vesicles prepared from human erythrocytes. Kinetic parameters for several GSH conjugates including S-(methyl)glutathione, S-(n-propyl)glutathione, S-(n-pentyl)glutathione, S-(n-decyl)glutathione, S-(p-chlorophenacyl)glutathione, S-(p-nitrobenzyl)glutathione, and the GSH conjugate of 9,10-epoxystearic acid were determined in order to evaluate their affinity for Dnp-SG ATPase. These studies reveal that all these conjugates stimulated Dnp-SG ATPase of human erythrocyte membrane. The apparent Kmvalues of Dnp-SG ATPase for different conjugates were found to be in the range of 0.26–0.66 mm with Vmaxvalues ranging from 0.55 to 4.44 nmol/min/mg protein. The results of these studies indicate that erythrocyte membrane Dnp-SG ATPase represents a generalized mechanism for the transport of GSH conjugates formed with xenobiotics as well as with the endogenously generated electrophilic compounds such as epoxystearic acid. It is suggested that Dnp-SG ATPase in conjunction with GSH and GSH S-transferase may play an important role in the protection of erythrocytes from exogenous as well as endogenous electrophilic toxicants.