Centruroides scorpion alpha-neurotoxin (α-NaTx)

Centruroides scorpion alpha-neurotoxins are a family of potent peptide toxins found in the venom of scorpions belonging to the genus Centruroides, most notably the Arizona bark scorpion (Centruroides sculpturatus) [PubMed: 21812505]. These toxins exert their effects by binding with high affinity to neurotoxin receptor site 3 on the voltage-gated sodium channels (Nav) of excitable cells [PubMed: 17174487]. By interacting with the extracellular loops of domain IV, they physically impede the movement of the voltage sensor required for fast inactivation, thereby slowing the closing of the channel [UniProt: P01492]. This results in prolonged sodium influx, leading to repetitive neuronal firing and a massive release of neurotransmitters. Clinically, this manifests as severe scorpion envenomation, characterized by autonomic storms, neuromuscular hyperactivity, and potential respiratory collapse. In medical practice, these toxins are the specific targets of therapeutic antivenoms, such as Centruroides immune F(ab')2 (Anascorp), which bind and neutralize the circulating toxins to prevent their interaction with host ion channels [FDA: Anascorp Label].

Other names

Centruroides alpha-toxinScorpion alpha-neurotoxinSite 3 sodium channel toxinCentruroides neurotoxin

Neutralization of circulating toxins by specific F(ab')2 antibody fragments, preventing the toxins from binding to neurotoxin receptor site 3 on voltage-gated sodium channels.