FEBS Letters | |
Binding of α‐tocopherylquinone, an oxidized form of α‐tocopherol, to glutathione‐S‐transferase in the liver cytosol | |
Arita, Makoto1  Sato, Yuji1  Arai, Hiroyuki1  Inoue, Keizo1  | |
[1] Department of Health Chemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan | |
关键词: α-Tocopherol; Antioxidant; α-Tocopherylquinone; Binding protein; Glutathione-S-transferase; Rat liver; αTTP; α-tocopherol transfer protein; GST; glutathione-S-transferase; | |
DOI : 10.1016/S0014-5793(98)01176-4 | |
学科分类:生物化学/生物物理 | |
来源: John Wiley & Sons Ltd. | |
【 摘 要 】
α-Tocopherol (vitamin E) is an important fat-soluble antioxidant in biological systems and, as a result of scavenging reactive oxygen, it is converted to α-tocopherylquinone. α-Tocopherol binds to α-tocopherol transfer protein (αTTP) in the liver cytosol, whereas α-tocopherylquinone does not. We found that α-tocopherylquinone binds to a liver protein with a molecular mass of about 40 kDa that is distinct from αTTP. This α-tocopherylquinone binding protein was purified further by multiple-step column chromatography. Sodium dodecylsulfate-polyacrylamide gel electrophoresis of the final preparation yielded a single band with an apparent molecular mass of 25 kDa, which microsequencing revealed was identical to glutathione-S-transferase (GST). The GST activity was inhibited in the presence of α-tocopherylquinone, as it is by other non-substrate ligands for GST, confirming that GST and α-tocopherylquinone interact directly. α-Tocopherylquinone binds to GST and may be transported to the site of metabolism or excreted in the bile as other non-substrate ligands for GST.
【 授权许可】
Unknown
【 预 览 】
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