Wikipedia
Taipoxin
Taipoxin is an extremely potent neurotoxin developed by purifying the venom of the Australian taipan Oxyuranus scutellatus. The toxin causes a gradual reduction to complete cessation of evoked and spontaneous release of acetylcholine from motor nerve terminals. The victim dies from asphyxia caused by paralysis of the respiratory muscles. It is the most lethal neurotoxin isolated from any snake venom to date.
The molecular mass of the heterotrimer is about 35,000 Dalton; comprising 1:1:1 α, β and γ monomers. Median lethal dose for mice was determined as 2 μg/kg ( subcutaneous injection).