Tirmenstein M A, Reed D J
Department of Biochemistry and Biophysics, Oregon State University, Corvallis 97331-6503.
Biochim Biophys Acta. 1989 Apr 6;995(2):174-80. doi: 10.1016/0167-4838(89)90077-0.
Glutathione protects isolated rat liver nuclei against lipid peroxidation by inducing a lag period prior to the onset of peroxidation. This GSH-dependent protection was abolished by exposing isolated nuclei to the glutathione S-transferase inhibitor S-octylglutathione. In incubations containing 0.2 mM S-octylglutathione, the GSH-induced lag period was reduced from 30 to 5 min. S-Octylglutathione (0.2 mM) also completely inhibited nuclear glutathione S-transferase activity and reduced glutathione peroxidase activity by 85%. About 70% of the glutathione S-transferase activity associated with isolated nuclei was solubilized with 0.3% Triton X-100. This solubilized glutathione S-transferase activity was partially purified by utilizing a S-hexylglutathione affinity column. The partially purified nuclear glutathione S-transferase exhibited glutathione peroxidase activity towards lipid hydroperoxides in solution. The data from the present study indicate that a glutathione S-transferase associated with the nucleus may contribute to glutathione-dependent protection of isolated nuclei against lipid peroxidation. Evidence was obtained which indicates that this enzyme is distinct from the microsomal glutathione S-transferase.
谷胱甘肽通过在过氧化开始前诱导一个延迟期来保护分离的大鼠肝细胞核免受脂质过氧化。将分离的细胞核暴露于谷胱甘肽S-转移酶抑制剂S-辛基谷胱甘肽后，这种依赖谷胱甘肽的保护作用被消除。在含有0.2 mM S-辛基谷胱甘肽的孵育中，谷胱甘肽诱导的延迟期从30分钟缩短至5分钟。0.2 mM的S-辛基谷胱甘肽还完全抑制了细胞核谷胱甘肽S-转移酶的活性，并使谷胱甘肽过氧化物酶的活性降低了85%。与分离的细胞核相关的约70%的谷胱甘肽S-转移酶活性可被0.3%的 Triton X-100溶解。利用S-己基谷胱甘肽亲和柱对这种溶解的谷胱甘肽S-转移酶活性进行了部分纯化。部分纯化的细胞核谷胱甘肽S-转移酶对溶液中的脂质氢过氧化物表现出谷胱甘肽过氧化物酶活性。本研究的数据表明，与细胞核相关的谷胱甘肽S-转移酶可能有助于依赖谷胱甘肽的分离细胞核免受脂质过氧化的保护。有证据表明，这种酶与微粒体谷胱甘肽S-转移酶不同。
