Figure A1. Matrix-assisted laser desorption time-of-flight mass spectrometry (MALDI-TOF-MS) spectrum of botulinum neurotoxin (BoNT) reactions. The top panel shows the MALDI-TOF-MS spectrum of the mixture of substrate peptides with no toxin present. The second panel shows this same mixture of substrate peptides and BoNT-A. The third, fourth and fifth panels show the mixture of substrate peptides with BoNT-B, -E, and –F, respectively. The insert mass spectrum for BoNT-E distinguishes the BoNT-dependent N-terminal product from the BoNT-A substrate peptide.