Botulinum neurotoxin C mutants reveal different effects of syntaxin or SNAP-25 proteolysis on neuromuscular transmission
(A) Digit Abduction Score (DAS) assay. 1 LD50 of BoNT/C-wt (cyan), or BoNT/C α-51 (green) or BoNT/C α-3W (red) were injected intramuscularly in the mice hind limb and neuroparalysis was evaluated according to . The rescue from paralysis was monitored daily until complete recovery was attained. Traces are representative of three independent experiments with at least 5 mice per condition. Error bars represent SEM (B) Analysis of evoked post synaptic junction potentials (EJP) on injected soleus muscles. Mice were treated as in A and at indicated time points soleus muscles were collected and processed for recordings of EJPs, as previously reported . Data are presented as a percentage of EJPs of control muscles. Each point represents an average EJP amplitude obtained from at least 45 muscle fibers from three different mice per condition. Statistical significance at each time point was determined by a student's t-test comparing the mean values between either BoNT/C α-51 (green) or BoNT/C α-3W (red) compared to BoNT/C-wt (cyan) (* p<0.05, ** p<0.01, *** p<0.001, **** p<0.0001, n.s. not significant). Error bars represent SEM.