Botulinum Neurotoxin Detection and Differentiation by Mass Spectrometry
Figure 1. Synaptobrevin on the synaptic vesicle must interact with syntaxin and SNAP (synaptosomal-associated protein)-25 on the neuronal membrane for fusion to occur, which allows the nerve impulse to be delivered across the synaptic junction. The botulinum neurotoxin serotypes cleave the peptide bonds at specific sites on the 3 proteins, as indicated. Cleavage of any 1 of these proteins prevents vesicle membrane docking and nerve impulse transmission.