人谷胱甘肽转移酶催化由有机亚硝酸盐和谷胱甘肽形成S-亚硝基谷胱甘肽的反应。

Human glutathione transferase catalysis of the formation of S-nitrosoglutathione from organic nitrites plus glutathione.

作者信息

Meyer D J, Kramer H, Ketterer B

机构信息

Department of Biochemistry and Molecular Biology, University College London, UK.

出版信息

FEBS Lett. 1994 Sep 12;351(3):427-8. doi: 10.1016/0014-5793(94)00904-x.

DOI:10.1016/0014-5793(94)00904-x

PMID:8082808

Abstract

The kinetics of spontaneous and human glutathione transferase catalysed formation of S-nitrosoglutathione (GSNO) from glutathione (GSH) and n-butyl- or amyl nitrite have been studied. At physiological pH and temperature, k2 values of 22.3 and 21.0 M-1.min-1 were obtained for n-butyl- and amyl nitrites, respectively. Rate enhancements, (kcat/Km x k2) x 10(-4), due to purified human GSH transferases A1-1, A2-2 and M1a-1a were, respectively, 7.00, 2.94 and 10.6 for n-butyl nitrite and 121, 3.92 and 34.5 for amyl nitrite. GSH transferase P1-1 showed no detectable catalysis of the formation of GSNO. The data suggest that the presence of GSTs A1-1, A2-2 or M1-1 contribute substantially to intracellular metabolism of alkyl nitrites to GSNO. The results may be significant with regard to the immunotoxicity of alkyl nitrites.

摘要

对谷胱甘肽（GSH）与亚硝酸正丁酯或亚硝酸戊酯自发形成S-亚硝基谷胱甘肽（GSNO）以及人类谷胱甘肽转移酶催化该反应的动力学进行了研究。在生理pH值和温度下，亚硝酸正丁酯和亚硝酸戊酯的k2值分别为22.3和21.0 M-1·min-1。纯化的人类谷胱甘肽转移酶A1-1、A2-2和M1a-1a对亚硝酸正丁酯的速率增强因子（kcat/Km×k2）×10(-4)分别为7.00、2.94和10.6，对亚硝酸戊酯的速率增强因子分别为121、3.92和34.5。谷胱甘肽转移酶P1-1对GSNO的形成未显示出可检测到的催化作用。数据表明，GSTs A1-1、A2-2或M1-1的存在对亚硝酸酯在细胞内代谢为GSNO有很大贡献。这些结果可能与亚硝酸酯的免疫毒性有关。