Comprehensive analysis of peptides and low molecular weight components of the giant ant Dinoponera quadriceps venom

Ants (Hymenoptera, Apocrita, Aculeata, Formicoidea) comprise a well-succeeded group of animals. Like bees and wasps, ants are mostly venomous, having a sting system to deliver a mixture of bioactive organic compounds and peptides. The predatory giant ant Dinoponera quadriceps belongs to the subfamily Ponerinae that include one of the largest known ant species in the world. In the present study, low molecular weight compounds and peptides were identified by on-line peptide mass fingerprint. These include neuroactive biogenic amines (histamine, tyramine, and dopamine), monoamine alkaloid (phenethylamine), free amino acids (e.g., glutamic acid and proline), free thymidine and cytosine. To the best of our knowledge most of these components are described for the first time in an ant venom. Multifunctional dinoponeratoxin peptides variants (pilosulin- and ponericin-like peptides) were characterized that possess antimicrobial, hemolytic, and histamine-releasing properties. These venom components, particularly peptides, might synergistically contribute to the overall venom activity and toxicity, for immobilizing live prey, and defending D. quadriceps against aggressors, predators and potential microbial infection.