Role of N-Terminal His6-Tags in Binding and Efficient Translocation of Polypeptides into Cells Using Anthrax Protective Antigen (PA)
Figure 2
Efficiency of HUVEC intoxication by C2I and His6-C2I using PA63 compared to PA F427A mutant.
HUVECs (5×105 cells/100 mm well) were intoxicated during 24 hours and the number of intoxicated cells (round cells) was assessed by counting floating cells. A: PA63 and C2II at 5 µg/ml and C2I and His6-C2I at 2 µg/ml. One representative experiment showing mean values of 5 independent counting for each condition. ± SEM *p<0.05 versus control condition. B: PA63 and PA F427A at 50 µg/ml and His6-C2I at 2 µg/ml. Data correspond to mean values of n = 5 experiments ± SEM, *p<0.05 versus control condition. The control corresponds to conditions without PA63. All experiments were performed with the same batch of cells at the same time. The 3-fold increase of toxicity using 10-fold more PA63 was repeatedly measured.