Alpha-neurotoxin (α-NTX) (α-NTX)

Alpha-neurotoxins are a major class of potent proteins found in the venom of elapid snakes, such as cobras and kraits, and are members of the three-finger toxin (3FTx) superfamily [UniProt: Family: Three-finger toxin family]. These toxins are characterized by a conserved structural motif of three beta-stranded loops extending from a hydrophobic core [Tsetlin, V. I. (1999). Eur. J. Biochem.]. Their primary biological function is the high-affinity, competitive antagonism of nicotinic acetylcholine receptors (nAChR) at the neuromuscular junction [Barber, C. M., et al. (2013). Toxicon]. By blocking acetylcholine binding, they prevent muscle depolarization, leading to progressive flaccid paralysis and potentially fatal respiratory failure [WHO Snakebite Envenoming]. In clinical practice, these toxins are the primary targets for neutralization by antivenoms, which consist of purified antibodies that bind the toxin and prevent its interaction with host receptors [StatPearls: Snake Toxicity]. While antivenoms are the standard of care, challenges include the rapid onset of action of these toxins and the risk of anaphylactic reactions to the treatment [PubMed: Antivenom Safety].

Other names

Three-finger toxin3FTxPostsynaptic neurotoxinSnake neurotoxinAlpha-bungarotoxinCobratoxin

Antivenoms neutralize the toxin by binding to its active sites or surrounding epitopes, sterically hindering the toxin's ability to bind to the nicotinic acetylcholine receptor and facilitating its systemic clearance.