Isomers in thioredoxins of spinach chloroplasts.
Isomers in thioredoxins of spinach chloroplasts.
复制标题
菠菜叶绿体硫氧还蛋白的异构体。
DOI：
10.1111/j.1432-1033.1981.tb05297.x
复制
发表时间：
1981
期刊：
影响因子：
--
通讯作者：
Akira Tsugita
中科院分区：
文献类型：
--
作者：
Peter Schürmann;Kayo Maeda;Akira Tsugita
我们开发了一种同时纯化菠菜叶绿体铁氧还蛋白/硫氧还蛋白系统的几个组分的方法。将该方法应用于菠菜叶提取物或菠菜叶绿体提取物中，我们分离纯化了三种叶绿体特有的硫氧还蛋白。当这三种硫氧还蛋白被还原时，将激活某些叶绿体酶，如果糖-1，6-二磷酸酶和依赖于NADP的苹果酸脱氢酶。果糖-1，6-二磷酸酶只被硫氧还蛋白f激活。苹果酸脱氢酶被硫氧还蛋白mb和硫氧还蛋白mc激活的方式相似，也被硫氧还蛋白f激活，但激活的动力学不同。三种硫氧还蛋白的相对分子质量非常相似，约为12,000，但等电点不同，分别为6.1(硫氧还蛋白f)、5.2(硫氧还蛋白mb)和5.0(硫氧还蛋白mc)。测定了每个硫氧还蛋白的氨基酸组成以及C-端和N-端序列。与m型硫氧还蛋白相比，硫氧还蛋白f在氨基酸组成和末端序列上表现出明显的差异。然而，硫氧还蛋白mb和硫氧还蛋白mc非常相似，唯一的区别是硫氧还蛋白mb的N末端有一个额外的赖氨酸残基。氨基酸分析、末端序列分析、免疫学测试和硫氧还蛋白的激活特性支持我们的结论：硫氧还蛋白mb和mc是来自同一基因的N末端冗余异构体，而硫氧还蛋白f是由不同基因编码的不同蛋白质。
We have developed a method for the concomitant purification of several components of the ferredoxin/thioredoxin system of spinach chloroplasts. By applying this method to spinach-leaf extract or spinach-chloroplast extract we separated and purified three thioredoxins indigenous to chloroplasts. The three thioredoxins, when reduced, will activate certain chloroplast enzymes such as fructose-1,6-bisphosphatase and NADP-dependent malate dehydrogenase. Fructose-1,6-bisphosphatase is activated by thioredoxin f exclusively. Malate dehydrogenase is activated by thioredoxin mb and thioredoxin mc in a similar way, and it is also activated by thioredoxin f but with different kinetics. All three thioredoxins have very similar relative molecular masses of about 12,000 but distinct isoelectric points of 6.1 (thioredoxin f), 5.2 (thioredoxin mb) and 5.0 (thioredoxin mc). The amino acid composition as well as the C-terminal and N-terminal sequences have been determined for each thioredoxin. Thioredoxin f exhibits clear differences in amino acid composition and terminal sequences when compared with the m-type thioredoxins. Thioredoxin mb and thioredoxin mc, however, are very similar, the only difference being an additional lysine residue at the N-terminus of thioredoxin mb. Amino acid analyses, terminal sequences, immunological tests and the activation properties of the thioredoxins support our conclusion that thioredoxins mb and mc are N-terminal redundant isomers coming from one gene whereas thioredoxin f is a different protein coded by a different gene.