Proteins toxic to arthropods in the venom of elapid snakes

Abstract

It has been found that the lethal action of elapid snake venoms to arthropods (fly larvae and isopods) is due to proteic factors differing from the toxins which are strongly and specifically active on mammals. This conclusion was based on the following: (1) Lack of any correlation between the toxic activity on larvae, isopods, and mice of ten elapid snake venoms. (2) Absence of any toxicity to arthropods in pure toxins isolated and purified from several elapid snake venoms according to their lethality. (3) Electrophoretical separation of the venom of the snake Naja mossambica mossambica (= N. nigricollis mossambica) resulted in fractions active either to arthropods and/or to mice. (4) Separation of the above venom by gel filtration on Sephadex G-50 enabled the isolation of fractions highly toxic to arthropods. (5) The above fractions demonstrated a high phospholipase activity corresponding to about 80 per cent of the total activity of the whole venom. The link between phospholipase and toxicity to arthropods will serve as a target for further investigation. It appears that the phenomenon of diversity in toxic activities of different proteins to different groups of organism, as previously demonstrated in scorpion venoms, is equally shared by elapid snake venoms.