Knocking out an animal 15 times your size — no problem. A newly identified toxin in the venom of a tropical centipede helps the arthropod to overpower giant prey in about 30 seconds.
Insight into how this venom overwhelms lab mice could lead to an antidote for people who suffer excruciatingly painful, reportedly even fatal, centipede bites, an international research team reports the week of January 22 in Proceedings of the National Academy of Sciences.
In Hawaii, centipede bites account for about 400 emergency room visits a year, according to data from 2004 to 2008. The main threat there is Scolopendra subspinipes, an agile species almost as long as a human hand.
The subspecies S. subspinipes mutilans starred in studies at the Kunming Institute of Zoology in China and collaborating labs. Researchers there found a small peptide, now named “spooky toxin,” largely responsible for venom misery.
This toxin blocks a molecular channel that normally lets potassium flow through cell membranes. A huge amount of the biochemistry of staying alive involves potassium, so clogging some of what are called KCNQ channels caused mayhem in mice: slow and gasping breath, high blood pressure, frizzling nerve dysfunctions and so on. Administering the epilepsy drug retigabine opened the potassium channels and counteracted much of the toxin’s effects, raising hopes of a treatment for these bites.