Taipoxin is a potent myo- and neurotoxin that was isolated from the venom of the coastal taipan Oxyuranus scutellatus or also known as the common taipan. Taipoxin like many other pre-synaptic neurotoxins are phospholipase A2 (PLA2) toxins, which inhibit/complete block the release of the motor transmitter acetylcholine and lead to death by paralysis of the respiratory muscles (asphyxia). It is the most lethal neurotoxin isolated from any snake venom to date.
The molecular mass of the heterotrimer is about 46,000 Dalton; comprising 1:1:1 α, β and γ monomers. Median lethal dose (LD50) for mice is around 1–2 μg/kg (subcutaneous injection).