EEF2 and diphtheria: In their works, incubation of rabbit reticulocyte lysates with diphtheria toxins converted all unbound EF2 to ADPR•EF2 and reduced the fraction of factor-bound ribosomes to half (25% → 12%), over two-third of which remained associated with native EF2 ( at 8.5%) while the rest with ADPR•EF2 ( at 3.5%).