BoNT/A HN

BoNTs (botulinum neurotoxin serotypes) act preferentially on cholinergic nerve endings to block acetylcholine release. The action of BoNTs involves three steps: (1) binding to receptors on the presynaptic membranes via the C-terminus of the heavy chain HC; (2) translocation of the light chain into the cytosol via the N-terminus of the heavy chain HN; and (3) cleavage of one or more key components in the synaptic vesicle docking and fusion protein complex by the zinc protease activity of the light chain.