The uncoupling protein from brown adipose tissue mitochondria is a dimer. A hydrodynamic study
The uncoupling protein from brown adipose tissue mitochondria is a dimer. A hydrodynamic study
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棕色脂肪组织线粒体的解偶联蛋白是二聚体。
DOI：
10.1016/0014-5793(80)80614-4
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发表时间：
1980
期刊：
影响因子：
3.5
通讯作者：
E.M. Klingenberg
中科院分区：
文献类型：
--
作者：
C.S. Lin;H. Hackenberg;E.M. Klingenberg
在前一篇文章中，我们描述了从棕色脂肪组织线粒体中纯化的一种嘌呤核苷酸结合蛋白，它似乎是这些线粒体所特有的解偶联因子[11]。该蛋白的纯度超过90%，与Triton X-100相关的产率相对较高。用十二烷基硫酸钠凝胶电泳法测定其亚基的相对分子质量为32000。溶解的蛋白质与线粒体中的GDP结合能力相同，表明分离的蛋白质在很大程度上保持了天然构象。GDP的结合位点数为16pmol/g蛋白质，对应的相对分子质量为62000。因此，推测该蛋白由两个32 000亚基组成的二聚体组成，其中一个结合位点为GDP。这种情况类似于线粒体的ADP，ATP载体，它的相对分子质量为60 000，有两个30 000的亚基和一个羧基苍术酸结合部位[2-41]。考虑到类似于ADP，ATP载体，可以预期溶解的解偶联蛋白以Triton含量较高的混合蛋白胶束的形式存在。水动力测量必须考虑到Triton的高含量。根据前面针对ADP，AT‘P载波[5，6]描述的技术，已经克服了Triton的干扰。
In the preceding paper we described the purification of a purine nucleotide binding protein from brown adipose tissue mitochondria which appears to be the uncoupling factor, peculiar to these mitochondria [11. The protein was obtained with more than 90% purity in relatively high yield associated with Triton X-100. The MW of its subunit was estimated by SDS gel electrophoresis to be 32 000. The solubilized protein has the same binding capacity for GDP as in mitochondria which indicates that the isolated protein has largely retained the native conformation. The number of binding sites for GDP was found to be 16 pmol/g protein, corresponding to a MW of 62 000. It was therefore suggested that the protein consists of a dimer of two subunits of 32 000 with one binding site of GDP. This case would be analogous to the ADP, ATP carrier of mitochondria which has a MW of 60 000 with two subunits of 30 000 and one binding site for carboxyatractylate [2-41.In the present paper we will present some data on the hydrodynamic properties of the isolated uncoupling protein with the aim of establishing its MW. In view of the analogy to the ADP, ATP carrier, the solubilized uncoupling protein can be expected to exist as a mixed protein Triton micelle with a high Triton content. Hydrodynamic measurements have to take into account the high content of Triton. Interference by Triton has been overcome according to the techniques described previously for the ADP, AT’P carrier [5, 6].