Botulinum neurotoxin serotype (A, B, C, D, E, F, or G) (BoNT (or BoNT/A, BoNT/B, etc.))

Botulinum neurotoxins are a family of highly potent bacterial protein toxins produced mainly by *Clostridium botulinum* and closely related species. They are divided into seven canonical serotypes, A through G, each with distinct antigenic properties and substrate specificities. The toxins are composed of a heavy chain (for neuron binding and translocation) and a light chain (a zinc-dependent endopeptidase) that specifically cleaves SNARE proteins necessary for synaptic vesicle fusion and neurotransmitter (acetylcholine) release at neuromuscular junctions. This action leads to the characteristic flaccid paralysis observed in botulism. BoNT/A and BoNT/B are most significant in human disease and are also used therapeutically for neuromuscular and cosmetic applications, while other serotypes have lesser human disease relevance or are more important in animal disease. Due to their extreme potency, safety in clinical use depends on precise dose control and monitoring[1][3][4][5][6].

Other names

Botulinum toxinBotulinum neurotoxinBotox (commercial name, for BoNT/A and BoNT/B)BoNT/A, BoNT/B, BoNT/C, BoNT/D, BoNT/E, BoNT/F, BoNT/G (as serotype short forms)

Cleavage of SNARE proteins (such as SNAP-25, VAMP, or syntaxin depending on serotype), preventing acetylcholine vesicle fusion and release at the neuromuscular junction[1][3][4][6].