Characterising the diversity of Neotropical and Australian ant venoms: novel peptide libraries for bioinsecticide discovery — The Association Specialists
  1. Schedule
  2. The 3 I's: Infection, Inflamation and Immunity
  3. Characterising the diversity of Neotropical and Australian ant venoms: novel peptide libraries for bioinsecticide discovery

Characterising the diversity of Neotropical and Australian ant venoms: novel peptide libraries for bioinsecticide discovery (300)

Samira R Aili 1 , Axel Touchard 2 3 , Matt P Padula 1 , Alain Dejean 3 , Jérôme Orivel 3 , Pierre Escoubas 2 , Graham M Nicholson 1
  1. School of Medical & Molecular Biosciences, University of Technology, Sydney, Broadway, NSW, Australia
  2. VenomeTech, 473 Route des Dolines — Villa 3, Valbonne, 06560, France
  3. Campus Agronomique, CNRS, UMR Ecologie des Forêts de Guyane (EcoFoG), Kourou, French Guiana, BP 316, 97379, France

Animal venom peptides are currently being developed as novel drugs and bioinsecticides. Given that ant venoms are used for predation and defence, venomous ants represent an untapped source of potential insecticidal toxins. In the present study, we compared the protein/peptide components and insecticidal properties of Pachycondyla commutata, Ectatomma tuberculatum, Odontomachus hastatus and Paraponera clavata venoms from French Guiana and Myrmecia gulosa from Australia. 1D and 2D gels of the venoms revealed proteins ranging from <10 kDa to >250 kDa. NanoESI-QTOF-MS/MS analysis of tryptic peptides confirmed the presence of common venom proteins but also many undescribed proteins. C18 reverse-phase HPLC separation followed by MALDI-TOF MS of the venoms was then undertaken and revealed considerable heterogeneity in the HPLC and mass profiles of the five venoms. Following optimisation of the MALDI matrix (α-cyano-4-hydroxycinnamic acid vs. ferrulic acid), and removal of potential adducts, it was found that venoms contained between 144–1032 peptides. In the case of Pachycondyla commutata, Paraponera clavata and O. hastatus venoms, 5–95% of peptides were between 1–4 kDa with the majority between 2–3 kDa, and 42 masses common to all three venoms. This mass range is lower than that of peptides from spider and scorpion venoms 1 , indicating likely novel peptide structures. Similar to arachnids, peptides from E. tuberculatum and M. gulosa venoms were distributed between 1–8 kDa (5–95% range) with the majority between 2–5 kDa. Using the reducing MALDI matrix 1,5-diaminonapthalene, disulfide-bonded peptides were also identified in all ant venoms (range 2–28). Acute toxicity testing of E. tuberculatum venom in house crickets revealed a 48 hr LD50 of 9 µg/g. Accordingly, bioassay-guided fractionation of this venom is currently being undertaken to identify insecticidal neurotoxins amenable for bioinsecticide development. In conclusion, these venoms represent a vast and untapped peptide library of potentially novel bioactive drug and insecticide leads.

  1. Palagi A, Koh JMS, Leblanc M, Wilson D, Dutertre S, King GF, Nicholson GM, Escoubas P (2013) Unravelling the complex venom landscapes of lethal Australian funnel-web spiders (Hexathelidae: Atracinae) using LC-MALDI-TOF mass spectrometry. Journal of Proteomics 80, 292–310.