Hydrogen Peroxide is Scavenged by Ascorbate-specific Peroxidase in Spinach Chloroplasts
Hydrogen Peroxide is Scavenged by Ascorbate-specific Peroxidase in Spinach Chloroplasts
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DOI：
10.1093/oxfordjournals.pcp.a076232
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发表时间：
1981-08
影响因子：
4.9
通讯作者：
Y. Nakano;K. Asada
中科院分区：
文献类型：
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作者：
Y. Nakano;K. Asada
完整的菠菜叶绿体通过一种以光还原剂为电子供体的过氧化物酶清除过氧化氢，但断裂的叶绿体的活性很低[Nakano和ASADA(1980)Plants&Cell Physiol]。21：1295]。破裂的菠菜叶绿体在加入谷胱甘肽和脱氢抗坏血酸(DHA)后，伴随着氧的释放，恢复了其光还原过氧化氢的能力。在破裂的叶绿体中，DHA被光还原为抗坏血酸，在谷胱甘肽存在的过程中放出氧气。DHA还原酶(EC 1.8.5.1)和一种电子供体为L抗坏血酸的过氧化物酶定位于叶绿体基质中。这些观察结果证实了叶绿体清除过氧化氢的电子供体是L抗坏血酸，而L抗坏血酸是由光系统I-铁还蛋白-谷胱甘肽再生的。给出了叶绿体过氧化物酶的初步表征。
Intact spinach chloroplasts scavenge hydrogen peroxide with a peroxidase that uses a photoreductant as the electron donor, but the activity of ruptured chloroplasts is very low [Nakano and Asada (1980) Plant & Cell Physiol. 21: 1295]. Ruptured spinach chloroplasts recovered their ability to photoreduce hydrogen peroxide with the concomitant evolution of oxygen after the addition of glutathione and dehydroascorbate (DHA). In ruptured chloroplasts, DHA was photoreduced to ascorbate and oxygen was evolved in the process in the presence of glutathione. DHA reductase (EC 1.8.5.1) and a peroxidase whose electron donor is specific to L-ascorbate are localized in chloroplast stroma. These observations confirm that the electron donor for the scavenging of hydrogen peroxide in chloroplasts is L-ascorbate and that the L-ascorbate is regenerated from DHA by the system: photosystem I-*ferredoxin-*NADP^>glutathione. A preliminary characterization of the chloroplast peroxidase is given.