Purification of Animal Neurotoxins

Using the same method of purification of small molecular weight proteins worked out to obtain pure scorpion neurotoxins, four neurotoxins have been isolated from the venom of the cobra Naja haje. N. haje venom from the Miami Serpentarium contains two neurotoxins (I and II) whereas the venom of the same species obtained from the Institut Pasteur contains three neurotoxins (I, II′ and III). Toxins I, II and II′ consist of 61 amino acid residues and toxin III of 71. All are basic proteins containing four or five disulphide bridges. It is likely that the difference observed in neurotoxin composition of N. haje venoms from two different sources has a taxonomical counterpart, each venom originating from a different sub‐species.