Oxyopinins are a group of peptide toxins present in the venom of lynx spiders belonging to the genus Oxyopes, from which they derive their name.
They are the largest linear cationic amphipathic peptides detected in the venom of any spider.
It is also 29% identical to the amino acid residues of the frog antimicrobial peptide dermaseptin.
They act together with neurotoxins called oxytoxins from the same venom for increased effectiveness as insecticide.
Further, unlike other arachnid toxins, Oxt-4a is very similar to defense peptides from the skin of frogs that contain the so-called Rana-box motif (a C-terminal disulfide-enclosed loop).