Abstract
The synthesis of glutathione peroxidase from [75Se]selenite was studied in slices and cell-free extracts from rat liver. The incorporation of [75Se]selenocysteine at the active site was detected by carboxymethylation and hydrolysis of partially purified glutathione peroxidase (glutathione:hydrogen peroxide oxidoreductase, EC 1.11.1.9) in the presence of [3H]selenocysteine and subsequent amino acid analysis. The synthesis of glutathione peroxidase in slices was inhibited by cycloheximide or puromycin and 75Se was incorporated from [75Se]selenite into free selenocysteine and selenocysteyl tRNA. Increasing concentrations of selenocystine caused a progressive dilution of the 75Se and a corresponding decrease in glutathione peroxidase labeling. In cell-free systems, [75Se]selenocysteyl tRNA was the best substrate for glutathione peroxidase synthesis. These results indicate the existence in rat liver of the de novo synthesis of free selenocysteine and a translational pathway of selenocysteine incorporation into glutathione peroxidase.
Original language | English (US) |
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Pages (from-to) | 225-234 |
Number of pages | 10 |
Journal | BBA - Gene Structure and Expression |
Volume | 739 |
Issue number | 2 |
DOIs | |
State | Published - Mar 10 1983 |
Keywords
- Glutathione peroxidase
- Selenocysteine, Selenite, Protein synthesis
- tRNA
ASJC Scopus subject areas
- Biochemistry
- Biophysics
- Genetics
- Structural Biology
- Medicine(all)