Opossum peptide may save lives lost to snakebites

Scientists have turned to the opossum -- a rat-like mammal found in the Americas -- to develop a promising new and inexpensive antidote for poisonous snake bites.

Presenting the results at the 249th meeting of the American Chemical Society, they predicted it could save thousands of lives worldwide without the side effects of current treatments.

Intriguingly, opossums shrug off snakebite venom with no ill-effects.

"Our approach is different because most anti-venoms are made by injecting the venom into a horse and then processing the serum," said Claire F. Komives from San Jose State University.

"The serum has additional components, however, so the patient often has some kind of adverse reaction, such as a rash, itching, wheezing, rapid heart rate, fever or body aches. The peptide we are using does not have those negative effects on mice," she added.

In the early 1990s, a group of researchers identified a serum protein from the opossum that was able to neutralise snake venoms.

One researcher found that a smaller chain of amino acids from the opossum protein, called a peptide, was also able to neutralise the venom.

Armed with this information, Komives and colleagues chemically synthesised the peptide. When they tested it in venom-exposed mice, they found that it protected them from the poisonous effects of bites from rattlesnakes and Russell's Viper venom.

"It appears that the venom protein may bind to the peptide, rendering it no longer toxic," Komives explained.

Komives' team showed that they could programme the bacteria E. coli to make the peptide. Producing the peptide in bacteria should enable the group to inexpensively make large quantities of it.

Komives said the anti-venom would probably work against venoms from other poisonous snakes, as well as against scorpion, plant and bacterial toxins.

Because the process is inexpensive, the anti-venom has a good chance of being distributed to underserved areas across the globe, which includes India, Southeast Asia, Africa and South America where poisonous snakes bite thousands of people every year.

Worldwide, an estimated 421,000 cases of poisonous snakebites and 20,000 deaths from these bites occur yearly.