DETOXICATION OF XENOBIOTICS IN ERYTHROCYTES

在人体组织中，如肝脏和肾脏，硫代尿酸途径 作为外源生物解毒的重要手段之一 外国化学品。然而，人类红细胞并不是完全的 硫代尿酸途径。红血球中含有大量的 硫代尿酸途径的第一个酶，谷胱甘肽S转移酶， 它将谷胱甘肽(GSH)偶联到大量疏水的 外源物质的携带和电生中心。我们最近做了 证明了1-氯-2，4-二硝基苯(CDNB)与1-氯-2，4-二硝基苯(CDNB) 谷胱甘肽在红细胞中形成。这种结合物不会进一步代谢 在这些细胞内，并被主动运输出红细胞。我们 建议研究GSH和GSH偶联物的转运机制 从人类红细胞中提取的外源生物。谷胱甘肽S转移酶将 从人类红血球中提纯至均一。纯化的酶将 将研究其对各种外源物质的动力学性质 也可用于合成谷胱甘肽和外源化合物的结合物， 将用于交通研究。黄曲霉毒素的输运动力学 将在正常和葡萄糖-6-磷酸脱氢酶中研究偶联物 缺陷的红细胞，重新密封的幽灵和由内而外形成的囊泡 红血球。为了更好地了解运输的机制 在结合物中，转运蛋白将被纯化，并 将在重组的蛋白脂质体中研究转运。自.以来 氧化的谷胱甘肽(GSSG)也是从 是的，我们将研究GSSG和GSH是否都是异种生物 结合物通过相同的转运蛋白运输。建议数 研究将对理解这一机制具有重要意义。 红血球可以解毒外源物质和环境污染物。

In human tissues such as liver and kidney, the mercapturic acid pathway serves as one of the important means of detoxifying the xenobiotics or foreign chemicals. However, human erythrocytes do not have complete mercapturic acid pathway. The erythrocytes contain high levels of the first enzyme of the mercapturic acid pathway, glutathione S-transferase, which conjugates glutathione (GSH) to a large number of the hydrophobic xenobiotics carrying and electrophylic center. We have recently demonstrated that the conjugate of 1-chlore-2,4-dinitrobenzene (CDNB) with GSH is formed in erythrocytes. This conjugate is not metabolized further within these cells and is actively transported out of the erythrocytes. We propose to study the mechanism of transport of the conjugates of GSH and xenobiotics from human erythrocytes. Glutathione S-transferase will be purified to homogeneity from human erythrocytes. The purified enzyme will be studied for its kinetic properties towards various xenobiotics and will also be used for the synthesis of conjugates of GSH and xenobiotics which will be used in transport studies. The kinetics of the transport of the conjugates will be studied in normal and glucose-6-phosphate dehydrogenase deficient erythrocytes, resealed ghosts and inside out vesicles formed from erythrocytes. In order to better understand the mechanism of the transport of the conjugates, the transporter protein will be purified and the transport will be studied in the reconstituted proteoliposomes. Since oxidized glutathione (GSSG) is also actively transported from the erythroctyes, we will study whether or not both GSSG and GSH-xenobiotic conjugates are transported via the same transporter protein. The proposed studies will be of great significance in understanding the mechanisms by which erythrocytes detoxify xenobiotics and environmental pollutants.