A major fraction of endoplasmic reticulum-located glutathione is present as mixed disulfides with protein
A major fraction of endoplasmic reticulum-located glutathione is present as mixed disulfides with protein
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DOI：
10.1074/jbc.m304951200
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发表时间：
2004-02-13
影响因子：
4.8
通讯作者：
Freedman, RB
中科院分区：
文献类型：
--
作者：
Bass, R;Ruddock, LW;Freedman, RB
三肽谷胱甘肽是真核细胞中最丰富的硫醇/二硫化物成分，已知存在于内质网腔中。因此，内质网腔的硫醇/二硫化物氧化还原状态由谷胱甘肽的状态定义，并且假设还原型和氧化型谷胱甘肽形成主要的氧化还原缓冲液。我们通过用硫醇特异性标记单溴二甲胺进行标记并随后通过反相高效液相色谱进行分离，确定了大鼠肝微粒体中谷胱甘肽在不同化学状态之间的分布。研究发现，超过一半的微粒体谷胱甘肽存在于与蛋白质的混合二硫化物中，其余部分以 3:1 的比例分布在还原型谷胱甘肽和氧化型谷胱甘肽之间。谷胱甘肽总量中被发现存在于与蛋白质混合的二硫键中的高比例对于内质网的氧化还原状态和缓冲能力以及因此对于体内二硫键的形成具有重要意义。
The tripeptide glutathione is the most abundant thiol/disulfide component of the eukaryotic cell and is known to be present in the endoplasmic reticulum lumen. Accordingly, the thiol/ disulfide redox status of the endoplasmic reticulum lumen is defined by the status of glutathione, and it has been assumed that reduced and oxidized glutathione form the principal redox buffer. We have determined the distribution of glutathione between different chemical states in rat liver microsomes by labeling with the thiol-specific label monobromobimane and subsequent separation by reversed phase high performance liquid chromatography. More than half of the microsomal glutathione was found to be present in mixed disulfides with protein, the remainder being distributed between the reduced and oxidized forms of glutathione in the ratio of 3:1. The high proportion of the total population of glutathione that was found to be in mixed disulfides with protein has significant implications for the redox state and buffering capacity of the endoplasmic reticulum and, hence, for the formation of disulfide bonds in vivo.