Presynaptic neurotoxin

Presynaptic neurotoxins are a functionally defined group of toxins—commonly found in animal venoms (notably snakes), Clostridium bacteria (e.g., botulinum, tetanus toxins), and some arthropods—that target the presynaptic terminals of neurons. They disrupt neurotransmitter release mechanisms, either by enzymatic cleavage of vesicle-associated proteins (e.g., SNARE proteins) or by damaging the presynaptic membrane (e.g., via phospholipase activity). The result is typically blockade of synaptic transmission at the neuromuscular junction, leading to neuroparalytic syndromes such as flaccid or spastic paralysis. Due to their high specificity and potency, some presynaptic neurotoxins have been studied for therapeutic use (e.g., botulinum toxin for spasticity) as well as for fundamental neuroscience research. The class is highly heterogeneous, with members varying in structure, mechanism, and clinical relevance[5][1][2][4].

Other names

β-neurotoxinpresynaptic toxinpre-junctional neurotoxin

Enzymatic cleavage of synaptic proteins (e.g., botulinum/tetanus toxins cleave SNARE proteins to prevent vesicle fusion); Phospholipid hydrolysis (specific snake PLA2 neurotoxins disrupt presynaptic membranes); Blockade or modulation of ion channels (some target Ca2+, K+, or other presynaptic ion channels)