OXIDIZED REDOX STATE OF GLUTATHIONE IN THE ENDOPLASMIC-RETICULUM
OXIDIZED REDOX STATE OF GLUTATHIONE IN THE ENDOPLASMIC-RETICULUM
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DOI：
10.1126/science.1523409
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发表时间：
1992-09-11
期刊：
影响因子：
56.9
通讯作者：
LODISH, HF
中科院分区：
文献类型：
--
作者：
HWANG, C;SINSKEY, AJ;LODISH, HF
内质网（ER）的氧化还原状态用肽N-Ace-tyl-Asn-Tyr-Thr-Cys-NH2测定。肽扩散穿过细胞膜；一些被糖基化，因此被困在分泌途径中，其半胱氨酸残基与周围的氧化还原缓冲液进行可逆的硫醇-二硫交换。来自细胞的糖基化肽与谷胱甘肽二硫连接，表明谷胱甘肽是分泌途径中的主要氧化还原缓冲物。分泌途径的氧化还原态比细胞质溶胶的氧化还原态更强；在分泌途径中还原性谷胱甘肽与二硫形式（GSH/GSSG）的比例为1:1至3:1，而整体细胞GSH/GSSG的比例为30:1至100:1。胞质谷胱甘肽也在无细胞系统中被转运到微粒体的腔内。虽然内质网维持氧化环境的方式尚不清楚，但这些结果表明，与谷胱甘肽相比，GSSG在内质网腔内的优先转运可能有助于这种氧化还原区室。
The redox state of the endoplasmic reticulum (ER) was measured with the peptide N-Ace-tyl-Asn-Tyr-Thr-Cys-NH2. The peptide diffused across cellular membranes; some became glycosylated and thus trapped within the secretory pathway, and its cysteine residue underwent reversible thiol-disulfide exchanges with the surrounding redox buffer. Glycosylated peptides from cells were disulfide-linked to glutathione, indicating that glutathione is the major redox buffer in the secretory pathway. The redox state of the secretory pathway was more oxidative than that of the cytosol; the ratio of reduced glutathione to the disulfide form (GSH/GSSG) within the secretory pathway ranged from 1:1 to 3:1, whereas the overall cellular GSH/GSSG ratio ranged from 30:1 to 100:1. Cytosolic glutathione was also transported into the lumen of microsomes in a cell-free system. Although how the ER maintains an oxidative environment is not known, these results suggest that the demonstrated preferential transport of GSSG compared to GSH into the ER lumen may contribute to this redox compartmentation.