Which snake's venom is the source of the neurotoxin α-bungarotoxin?

The many-banded krait is the snake whose venom is the source of the neurotoxin α-bungarotoxin. Its scientific name is Bungarus multicinctus, and it is also called the Taiwanese banded krait, Chinese krait, or Taiwanese krait.

α-Bungarotoxin is a powerful postsynaptic neurotoxin. It binds very tightly, effectively irreversibly, to nicotinic acetylcholine receptors at neuromuscular junctions. By blocking acetylcholine from activating those receptors, it prevents nerve signals from making skeletal muscles contract. Severe envenomation can therefore progress to paralysis and respiratory failure.

The toxin became especially important in neuroscience because researchers can attach fluorescent labels to it and use it to locate acetylcholine receptors in muscle and nervous tissue. Studies of many-banded krait venom at National Taiwan University in the 1950s and 1960s helped separate α-bungarotoxin from related bungarotoxins, including β-bungarotoxin.

Cobras, coral snakes, and black mambas also possess dangerous neurotoxins, but α-bungarotoxin’s name and canonical source point specifically to Bungarus multicinctus venom.