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The thioredoxin and glutaredoxin systems are efficient electron donors to human plasma glutathione peroxidase

Björnstedt, Mikael ; Xue, Jiyan ; Huang, Wenhu ; Åkesson, Björn LU and Holmgren, Arne (1994) In Journal of Biological Chemistry 269(47). p.29382-29384
Abstract
Human plasma glutathione peroxidase (GSH-Px) is a distinct extracellular selenoenzyme that detoxifies hydroperoxides when used with GSH in high (mM) non-physiological concentrations. We have discovered that NADPH and human thioredoxin reductase (TR) by itself or with thioredoxin (Trx) are efficient electron donors to this human plasma peroxidase. Incubation of 0.05 microM TR with 0.25 microM GSH-Px, in a system free from GSH, resulted in reduction of t-butyl hydroperoxide. Addition of Trx, 2.5 and 5 microM, respectively, further increased the rate of the reaction. These data were obtained using an assay measuring the oxidation of NADPH. A direct assay demonstrated the formation of cumyl alcohol from cumene hydroperoxide in this... (More)
Human plasma glutathione peroxidase (GSH-Px) is a distinct extracellular selenoenzyme that detoxifies hydroperoxides when used with GSH in high (mM) non-physiological concentrations. We have discovered that NADPH and human thioredoxin reductase (TR) by itself or with thioredoxin (Trx) are efficient electron donors to this human plasma peroxidase. Incubation of 0.05 microM TR with 0.25 microM GSH-Px, in a system free from GSH, resulted in reduction of t-butyl hydroperoxide. Addition of Trx, 2.5 and 5 microM, respectively, further increased the rate of the reaction. These data were obtained using an assay measuring the oxidation of NADPH. A direct assay demonstrated the formation of cumyl alcohol from cumene hydroperoxide in this GSH-independent peroxidase reaction. Incubation of 0.25 microM GSH-Px with a low concentration of GSH (10 microM), representing the upper level in plasma, plus excess glutathione reductase and NADPH did not result in any reduction of t-butyl hydroperoxide. However, after addition of 2.5 microM human glutaredoxin, a linear peroxidase reaction started. The results suggest that extracellular TR, Trx, or glutaredoxin are reductants for the selenium-dependent peroxidase rather than GSH. (Less)
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type
Contribution to journal
publication status
published
subject
in
Journal of Biological Chemistry
volume
269
issue
47
pages
3 pages
publisher
American Society for Biochemistry and Molecular Biology
external identifiers
  • scopus:0028139014
ISSN
1083-351X
language
English
LU publication?
yes
id
a418b2c9-bcaa-4c50-a93a-fd2df2aaddab
alternative location
https://www.jbc.org/content/269/47/29382.short
date added to LUP
2019-06-26 08:57:35
date last changed
2024-01-04 22:30:23
@article{a418b2c9-bcaa-4c50-a93a-fd2df2aaddab,
  abstract     = {{Human plasma glutathione peroxidase (GSH-Px) is a distinct extracellular selenoenzyme that detoxifies hydroperoxides when used with GSH in high (mM) non-physiological concentrations. We have discovered that NADPH and human thioredoxin reductase (TR) by itself or with thioredoxin (Trx) are efficient electron donors to this human plasma peroxidase. Incubation of 0.05 microM TR with 0.25 microM GSH-Px, in a system free from GSH, resulted in reduction of t-butyl hydroperoxide. Addition of Trx, 2.5 and 5 microM, respectively, further increased the rate of the reaction. These data were obtained using an assay measuring the oxidation of NADPH. A direct assay demonstrated the formation of cumyl alcohol from cumene hydroperoxide in this GSH-independent peroxidase reaction. Incubation of 0.25 microM GSH-Px with a low concentration of GSH (10 microM), representing the upper level in plasma, plus excess glutathione reductase and NADPH did not result in any reduction of t-butyl hydroperoxide. However, after addition of 2.5 microM human glutaredoxin, a linear peroxidase reaction started. The results suggest that extracellular TR, Trx, or glutaredoxin are reductants for the selenium-dependent peroxidase rather than GSH.}},
  author       = {{Björnstedt, Mikael and Xue, Jiyan and Huang, Wenhu and Åkesson, Björn and Holmgren, Arne}},
  issn         = {{1083-351X}},
  language     = {{eng}},
  number       = {{47}},
  pages        = {{29382--29384}},
  publisher    = {{American Society for Biochemistry and Molecular Biology}},
  series       = {{Journal of Biological Chemistry}},
  title        = {{The thioredoxin and glutaredoxin systems are efficient electron donors to human plasma glutathione peroxidase}},
  url          = {{https://www.jbc.org/content/269/47/29382.short}},
  volume       = {{269}},
  year         = {{1994}},
}