Botulinum Neurotoxin G (BoNT/G)

Botulinum Neurotoxin G (BoNT/G) is a highly potent neurotoxin produced by Clostridium botulinum. It is one of seven serotypes (A-G) of botulinum toxins. BoNT/G inhibits neurotransmitter release at neuromuscular junctions, leading to flaccid paralysis. The toxin consists of a light chain (LC) that cleaves SNARE proteins, specifically VAMP/synaptobrevin, and a heavy chain (HC) responsible for neuronal binding and translocation. It binds to gangliosides (like GD1a) and protein receptors (Synaptotagmin I) on presynaptic membranes. BoNT/G exists in complexes with non-toxic associated proteins (NAPs) that stabilize the toxin. Its mechanism of action involves binding, endocytosis, translocation of the LC, and cleavage of VAMP/synaptobrevin, ultimately blocking acetylcholine release.

BoNT/G binds to neuronal receptors (gangliosides like GD1a and Synaptotagmin I), is endocytosed, and translocates its light chain into the cytoplasm. The light chain then cleaves VAMP/synaptobrevin, a SNARE protein, preventing acetylcholine release and causing flaccid paralysis.