Evidence for the presence of the ascorbate-glutathione cycle in mitochondria and peroxisomes of pea leaves
Evidence for the presence of the ascorbate-glutathione cycle in mitochondria and peroxisomes of pea leaves
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DOI：
10.1104/pp.114.1.275
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发表时间：
1997-05-01
期刊：
影响因子：
7.4
通讯作者：
Sevilla, F
中科院分区：
文献类型：
--
作者：
Jimenez, A;Hernandez, JA;Sevilla, F
抗坏血酸-谷胱甘肽循环的酶的存在下进行了研究，在线粒体和过氧化物酶体纯化豌豆（豌豆L。）叶子所有四种酶，抗坏血酸过氧化物酶（APX; EC 1.11.1.11），单脱氢抗坏血酸还原酶（EC 1.6.5.4），脱氢1.8.5.1坏血酸还原酶（EC1.6.4.2）和谷胱甘肽还原酶（EC www.example.com），存在于线粒体和过氧化物酶体，以及抗氧化剂抗坏血酸和谷胱甘肽。抗坏血酸-谷胱甘肽循环酶的活性在线粒体中比在过氧化物酶体中高，除了APX，其在过氧化物酶体中比在线粒体中更活跃。完整的线粒体和过氧化物酶体没有潜在的APX活性，这仍然是在膜级分后，用0.2 M KCl溶解试验。单脱氢抗坏血酸还原酶是高度潜伏在完整的线粒体和过氧化物酶体和膜结合，这表明该氧化还原蛋白的电子受体和供体位点不在线粒体和过氧化物酶体膜的外侧。脱氢抗坏血酸还原酶主要存在于可溶性过氧化物酶体和线粒体组分中。谷胱甘肽还原酶在线粒体和过氧化物酶体中有很高的潜伏期，并且存在于两种细胞器的可溶性组分中。在完整的过氧化物酶体和线粒体，还原型抗坏血酸和谷胱甘肽和抗坏血酸和谷胱甘肽的氧化形式的存在下，证明了通过高效液相色谱分析。线粒体和过氧化物酶体的抗坏血酸-谷胱甘肽循环可能是一个重要的抗氧化保护系统，对H2 O2产生的植物细胞器。
The presence of the enzymes of the ascorbate-glutathione cycle was investigated in mitochondria and peroxisomes purified from pea (Pisum sativum L.) leaves. All four enzymes, ascorbate peroxidase (APX; EC 1.11.1.11), monodehydroascorbate reductase (EC 1.6.5.4), dehydroascorbate reductase (EC 1.8.5.1), and glutathione reductase (EC 1.6.4.2), were present in mitochondria and peroxisomes, as well as in the antioxidants ascorbate and glutathione. The activity of the ascorbate-glutathione cycle enzymes was higher in mitochondria than in peroxisomes, except for APX, which was more active in peroxisomes than in mitochondria. Intact mitochondria and peroxisomes had no latent APX activity, and this remained in the membrane fraction after solubilization assays with 0.2 M KCI. Monodehydroascorbate reductase was highly latent in intact mitochondria and peroxisomes and was membrane-bound, suggesting that the electron acceptor and donor sites of this redox protein are not on the external side of the mitochondrial and peroxisomal membranes. Dehydroascorbate reductase was found mainly in the soluble peroxisomal and mitochondrial fractions. Glutathione reductase had a high latency in mitochondria and peroxisomes and was present in the soluble fractions of both organelles. In intact peroxisomes and mitochondria, the presence of reduced ascorbate and glutathione and the oxidized forms of ascorbate and glutathione were demonstrated by high-performance liquid chromatography analysis. The ascorbate-glutathione cycle of mitochondria and peroxisomes could represent an important antioxidant protection system against H2O2 generated in both plant organelles.