Australasian Science: Australia's authority on science since 1938

Anti-freeze Venom

By Stephen Luntz

Most venoms don’t work at very cold temperatures, which makes the poison produced by the Antarctic octopus particularly interesting.

The idea of putting animal venoms to use in the production of drugs, particularly painkillers, is not new (AS, Jan/Feb 2010, p.39). However, most venoms don’t work at very cold temperatures, which makes the poison produced by the Antarctic octopus particularly interesting.

Dr Bryan Fry of the University of Melbourne’s Bio21 Institute led an expedition that collected 203 specimens, including what appear to be four new species, one of which will require its own genus. “This is the first study that has collected Antarctic octopus venom and confirmed that these creatures have adapted it to work in subzero temperatures,” Fry says. “The next step is to work out what biochemical tricks they have used.”

Like most venoms, there are a range of toxins in the octopus venom, two of which have not previously been described. “We have discovered new small proteins in the venom with very intriguing activities,” Fry says. “These are potentially useful in drug design, but more will be revealed as the study continues.

“Venoms are rare combinations of very potent yet precisely targeted chemicals: the ultimate smart bombs,” Fry says. While it is not always easy to work out how a venom can be put to use, Fry says that the neuroactive molecules in these venoms will be investigated as painkillers first.

These octopi survive at temperatures below zero, with the water’s salt content keeping it from freezing. Temperature is the major determinant of enzyme activity, so most venoms will not operate below 0°C. Fry describes the Antarctic octopi as producing “the equivalent of anti-freeze venom”.

In 2009 Fry demonstrated that all octopi are venomous (AS, Jan/Feb 2006, p.6).