Copper-zinc superoxide dismutase is a constituent enzyme of the matrix of peroxisomes in the cotyledons of oilseed plants
Copper-zinc superoxide dismutase is a constituent enzyme of the matrix of peroxisomes in the cotyledons of oilseed plants
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DOI：
10.1046/j.1469-8137.1998.00899.x
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发表时间：
1998-02-01
期刊：
影响因子：
9.4
通讯作者：
Trelease, RN
中科院分区：
文献类型：
--
作者：
Corpas, FJ;Sandalio, LM;Trelease, RN
比较了3种不同油料种子幼苗子叶线粒体和过氧化物酶体中超氧化物歧化酶（SOD）同工酶的数量、类型及其活性。线粒体和过氧化物酶体亚型的SOD可以区分在非变性聚丙烯酰胺凝胶由其不同的敏感性KCN和/或H2 O2。3种油料种子中各细胞器SOD的类型不同。例如，在棉花和黄瓜线粒体中发现了单一的Mn-SOD，而向日葵线粒体中存在四种CuZn-SOD。在所有三个物种的过氧化物酶体中发现至少一种CuZn-SOD同工型。黄瓜过氧化物酶体中同时含有CuZn-SOD和Mn-SOD，棉花过氧化物酶体中含有单一的CuZn-SOD，向日葵过氧化物酶体中含有4个CuZn-SOD，但不含Mn-SOD。利用抗西瓜过氧化物酶体或木贼叶绿体CuZn-SOD的抗体，从西瓜中提取了一种单一的多肽。16.5 kDa的过氧化物酶体组分从三个物种的免疫印迹检测。包埋后，电子显微镜双免疫金标记表明，CuZn-SOD，苹果酸合成酶作为过氧化物酶体的标记酶，被定位在所有三个物种的这些细胞器的矩阵。这些结果表明，CuZn-SOD是油菜子叶过氧化物酶体的特征性基质酶。
The number and type of isoforms of superoxide dismutase (SOD) and their activities were compared in mitochondria and peroxisomes isolated from cotyledons of three different oilseed seedlings. Mitochondrial and peroxisomal isoforms of SOD could be distinguished in nondenaturing polyacrylamide gels by their differential sensitivities to KCN and/or H2O2. The type of SOD was not the same for each organelle in each of the three oilseed species. For example, a single Mn-SOD was found in cotton and cucumber mitochondria, whereas four CuZn-SODs were present in mitochondria from sunflower. At least one CuZn-SOD isoform was found in the peroxisomes of all three species. Cucumber peroxisomes contained both a CuZn-SOD and a Mn-SOD, cotton peroxisomes contained a single CuZn-SOD, whilst four separate CuZn-SODs, but no Mn-SOD were found in sunflower peroxisomes. Using antibodies against CuZn-SOD from watermelon peroxisomes or from chloroplasts of Equisetum, a single polypeptide of c. 16.5 kDa was detected on immunoblots of peroxisomal fractions from the three species. Post-embedment, electron-microscopic double immunogold-labelling showed that CuZn-SOD, with malate synthase used as marker enzyme of peroxisomes, was localized in the matrix of these organelles of all three species. These results suggest that CuZn-SOD is a characteristic matrix enzyme of peroxisomes in oilseed cotyledons.