title: Studies on the inhibition of protein synthesis by selenodiglutathione.
abstract: Amino acid incorporation in a cell-free system derived from rat liver has previously been found to be inhibited by GSSeSG (selenodiglutathione). In the present experiments the effect of GSSeSG on protein synthesis in 3T3-f cells, on growth and protein synthesis in Escherichia coli, and on amino acid incorporation in a cell-free system derived from E. coli, was studied. GSSeSG inhibits the incorporation of [3H]leucine into protein by 3T3-f cells. This inhibition cannot be reversed by removing GSSeSG and is correlated with the uptake of GSSeSG. Sodium selenite (Na2SeO3) and oxidized glutathione had no inhibitory effect in this system. [3H]Uridine or [3H]thymidine incorporation into RNA or DNA was not inhibited, indicating that the primary action of GSSeSG was on protein synthesis. GSSeSG did not influence the growth of E. coli in a synthetic medium, although enhanced amino acid incorporation was observed. In the cell-free system derived from E. coli, amino acid incorporation was not changed by GSSeSG, indicating that elongation factor G, in contrast to elongation factor 2 of mammalian cell systems, is not blocked by GSSeSG.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002474:Cell-Free System / Q000187:drug effects; D004247:DNA / Q000096:biosynthesis; D004926:Escherichia coli / Q000187:drug effects / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives* / Q000378:metabolism; D014176:Protein Biosynthesis; D012313:RNA / Q000096:biosynthesis; D051381:Rats; D012643:Selenium
chemical_list: D000596:Amino Acids; D012313:RNA; D004247:DNA; D005978:Glutathione; D012643:Selenium