Mechanism of inhbition of protein systhesis initiation by diacetoxyscirpenol and fusarenon X in the reticulocyte lysate system.

The mechanism of inhibition of peptide chain initiation by diacetoxyscirpenol and fusarenon X, (trichotecene mycotoxins), was studied in the reticulocyte lysate protein-synthesizing system. The mycotoxins did not inhibit formation of the complex between Met-tRNA-f and the 40S ribosomal subunit nor the initiation codon AUG-promoted combination of the complex with 60S ribosomal subunit. Formyl-methionyl-valine accumulated when the system was incubated with the mycotoxins and fMet-tRNA-f. This suggests that the inhibition occurs after the formation of the first peptide bond.