Glutathione transferases are detoxifying enzymes responsible for eliminating toxic compounds generated under a variety of stress conditions. Saccharomyces cerevisiae control cells and glutathione transferase mutant strains (gtt1 and gtt2) were used to analyze tolerance, lipid and protein oxidation as oxidative stress markers during growth in the presence of H2O2. Glucose 6-phosphate dehydrogenase (G6PD) and glutathione reductase were assayed to monitor the capacity of cells to recycle glutathione. Although a reduction in growth was observed, deletion of GTT1 showed less inhibition by H2O2 than the control strain. Cells showed a significant reduction in cellular viability during the first hours of growth, the gtt1 mutant being hypersensitive even after 24 h of H2O2 exposure. As a consequence of oxidative stress caused by exposure to H2O2, an increase in lipid peroxidation was observed, mainly in the glutathione transferase mutant strains. While protein carbonylation increased by 17% and 23%, respectively, after 2 h in the presence of H2O2 in the control and gtt2 mutant, a 40% increase was observed in the gtt1 strain after 24-h exposure. The antioxidant G6PD and glutathione reductase activities were affected in the gtt1 mutant during H2O2 exposure, which could be critical for recycling glutathione. The same was observed for the gtt2 mutant after 2-h treatment, indicating that glutathione recycling might be associated with the detoxification process. Thus, glutathione transferases, Gtt1 and Gtt2, seem to be crucial in the response to H2O2 stress.

中文翻译：

---

谷胱甘肽转移酶Gtt1和Gtt2参与酿酒酵母生长过程中H2O2产生的氧化应激反应。

谷胱甘肽转移酶是排毒酶，负责消除在各种压力条件下产生的有毒化合物。酿酒酵母控制细胞和谷胱甘肽转移酶突变菌株（gtt1和gtt2）被用来分析在H2O2存在下生长过程中的耐受性，脂质和蛋白质氧化作为氧化应激标记。分析葡萄糖6-磷酸脱氢酶（G6PD）和谷胱甘肽还原酶以监测细胞回收谷胱甘肽的能力。尽管观察到生长减少，但是与对照菌株相比，GTT1的缺失显示出对H 2 O 2的抑制作用较小。细胞在生长的最初几个小时内显示出细胞活力的显着降低，即使在暴露于H2O2 24小时之后，gtt1突变体仍会过敏。由于暴露于H2O2导致氧化应激的结果，观察到脂质过氧化增加，主要在谷胱甘肽转移酶突变株中。尽管蛋白质羰基化在对照和gtt2突变体中存在H2O2后2小时后分别增加了17％和23％，但在暴露24小时后gtt1菌株中观察到了40％的增加。在暴露于H2O2的过程中，gtt1突变体的抗氧化剂G6PD和谷胱甘肽还原酶活性受到影响，这对于回收谷胱甘肽至关重要。在2小时的治疗后，对gtt2突变体观察到了同样的情况，这表明谷胱甘肽循环可能与解毒过程有关。因此，谷胱甘肽转移酶Gtt1和Gtt2，似乎对H2O2压力的反应至关重要。尽管蛋白质羰基化在对照和gtt2突变体中存在H2O2后2小时后分别增加了17％和23％，但在暴露24小时后gtt1菌株中观察到了40％的增加。在暴露于H2O2的过程中，gtt1突变体的抗氧化剂G6PD和谷胱甘肽还原酶活性受到影响，这对于回收谷胱甘肽至关重要。在2小时的治疗后，对gtt2突变体观察到了同样的情况，这表明谷胱甘肽循环可能与解毒过程有关。因此，谷胱甘肽转移酶Gtt1和Gtt2，似乎对H2O2压力的反应至关重要。尽管蛋白质羰基化在对照和gtt2突变体中存在H2O2后2小时后分别增加了17％和23％，但在暴露24小时后gtt1菌株中观察到了40％的增加。在暴露于H2O2的过程中，gtt1突变体的抗氧化剂G6PD和谷胱甘肽还原酶活性受到影响，这对于回收谷胱甘肽至关重要。在2小时的治疗后，对gtt2突变体观察到了相同的结果，这表明谷胱甘肽循环可能与解毒过程有关。因此，谷胱甘肽转移酶Gtt1和Gtt2，似乎对H2O2压力的反应至关重要。在暴露于H2O2的过程中，gtt1突变体的抗氧化剂G6PD和谷胱甘肽还原酶活性受到影响，这对于回收谷胱甘肽至关重要。在2小时的治疗后，对gtt2突变体观察到了同样的情况，这表明谷胱甘肽循环可能与解毒过程有关。因此，谷胱甘肽转移酶Gtt1和Gtt2，似乎对H2O2压力的反应至关重要。在暴露于H2O2的过程中，gtt1突变体的抗氧化剂G6PD和谷胱甘肽还原酶活性受到影响，这对于回收谷胱甘肽至关重要。在2小时的治疗后，对gtt2突变体观察到了同样的情况，这表明谷胱甘肽循环可能与解毒过程有关。因此，谷胱甘肽转移酶Gtt1和Gtt2，似乎对H2O2压力的反应至关重要。