Chemistry that delighted us in 2021

Abstract

Snakes spitting pain Most of the venomous snakes in the Liverpool School of Tropical Medicine’s collection immobilize and kill prey by injecting venom through their fangs. But some snakes protect themselves from predators by spitting venom —potentially causing pain, inflammation, and blindness. This year, a team of researchers at the school’s Centre for Snakebite Research and Interventions uncovered how the venom packs such a punch: the molecular cocktail in spitting snakes’ venom contains high levels of proteins that increase the sensation of pain ( Science 2021, DOI: 10.1126/science.abb9303 ). The team found that, while each snake’s venom had a unique concoction of toxins, all the spitting snakes had higher levels of phospholipase A 2 (PLA 2 ) enzymes in their venom than nonspitting snakes. In tests on mouse nerve cells, mixtures of venom components including PLA 2 triggered more cell activity than cocktails without it, a sign of a greater