Alpha-bungarotoxin (α-BTX) (α-BTX)

Alpha-bungarotoxin and related low molecular weight neurotoxins from the kraits Bungarus multicinctus and Bungarus candidus are potent members of the three-finger toxin (3FTx) family (UniProt P01378, P01377). These toxins function as highly specific and nearly irreversible antagonists of the nicotinic acetylcholine receptor (nAChR) at the postsynaptic membrane of the neuromuscular junction (Nirthanan & Gwee, 2004). By blocking the binding of the neurotransmitter acetylcholine, these toxins prevent muscle contraction, leading to progressive flaccid paralysis and potentially fatal respiratory failure in envenomed victims (WHO, 2016). While these neurotoxins are not therapeutic targets for treating human diseases, they are the primary pathological agents targeted for neutralization by antivenom therapy (StatPearls, 2023). In pharmacological research, alpha-bungarotoxin has served as a gold-standard tool for labeling and studying the distribution of nAChRs in the nervous system. Clinical management of envenomation relies on the timely administration of specific antivenoms, which contain antibodies that bind and sequester the toxins in the circulation (WHO, 2016). The high affinity of these toxins for their receptor makes them both a significant clinical challenge and a powerful tool in molecular biology.

Other names

α-Bungarotoxinα-BTXMany-banded krait neurotoxinMalayan krait neurotoxinThree-finger toxin3FTxPostsynaptic neurotoxin type I

Antivenoms neutralize the toxins by binding to their active epitopes, preventing the toxins from interacting with the nicotinic acetylcholine receptors (nAChR) at the neuromuscular junction (WHO, 2016; StatPearls, 2023).