Di Ilio C, Sacchetta P, Lo Bello M, Caccuri A M, Federici G
J Mol Cell Cardiol. 1986 Sep;18(9):983-91. doi: 10.1016/s0022-2828(86)80012-8.
Glutathione peroxidase activity with both hydrogen peroxide and cumene hydroperoxide was measured in the cytosolic fractions prepared from five human hearts obtained from post-mortem victims. In all the samples the activity with cumene hydroperoxide was higher than that obtained with hydrogen peroxide, suggesting that the selenium-independent glutathione peroxidase could also be present in this tissue. To determine its presence in heart tissue we fractionated the cardiac cytosol fraction on a column of Sephadex G-100 and measured glutathione peroxidase activity with both the substrates. Glutathione transferase activity was measured with 1-chloro-2,4-dinitrobenzene in the fractionated cytosol. The results indicated that a selenium-independent glutathione peroxidase activity was present (about 30% of total activity). Fractionation of the cytosol by gel filtration showed that peroxidase activity co-eluted with glutathione transferase activity. Subsequently the fractions containing glutathione transferase and selenium-independent glutathione peroxidase activity obtained from gel filtration experiments were passed through an affinity column and analyzed by isoelectric focusing. It was found that the selenium-independent glutathione peroxidase copurified with three isoenzymes of glutathione transferase which had a pI of 9.2, 8.9 and 8.6 respectively. In contrast the acidic isoenzymes of glutathione transferase lacked peroxidase activity. It is suggested that the selenium-independent glutathione peroxidase may play an important role in neutralizing oxygen toxicity in heart when the selenium-dependent glutathione peroxidase activity is impaired.
在从五名尸检受害者获取的人心脏中制备的胞质部分中，测量了过氧化氢和氢过氧化异丙苯存在下的谷胱甘肽过氧化物酶活性。在所有样品中，氢过氧化异丙苯存在下的活性高于过氧化氢存在下的活性，这表明该组织中也可能存在不依赖硒的谷胱甘肽过氧化物酶。为了确定其在心脏组织中的存在，我们在Sephadex G - 100柱上对心脏胞质部分进行分级分离，并测量两种底物存在下的谷胱甘肽过氧化物酶活性。在分级分离的胞质中用1 - 氯 - 2,4 - 二硝基苯测量谷胱甘肽转移酶活性。结果表明存在不依赖硒的谷胱甘肽过氧化物酶活性（约占总活性的30%）。通过凝胶过滤对胞质进行分级分离表明，过氧化物酶活性与谷胱甘肽转移酶活性共洗脱。随后，将从凝胶过滤实验中获得的含有谷胱甘肽转移酶和不依赖硒的谷胱甘肽过氧化物酶活性的部分通过亲和柱，并通过等电聚焦进行分析。发现不依赖硒的谷胱甘肽过氧化物酶与三种谷胱甘肽转移酶同工酶共纯化，它们的等电点分别为9.2、8.9和8.6。相比之下，谷胱甘肽转移酶的酸性同工酶缺乏过氧化物酶活性。有人提出，当依赖硒的谷胱甘肽过氧化物酶活性受损时，不依赖硒的谷胱甘肽过氧化物酶可能在中和心脏中的氧毒性方面发挥重要作用。
