Ponericins, New Antibacterial and Insecticidal Peptides from the Venom of the Ant Pachycondyla goeldii

Abstract

The antimicrobial, insecticidal, and hemolytic properties of peptides isolated from the venom of the predatory ant Pachycondyla goeldii, a member of the subfamily Ponerinae, were investigated. Fifteen novel peptides, named ponericins, exhibiting antibacterial and insecticidal properties were purified, and their amino acid sequences were characterized. According to their primary structure similarities, they can be classified into three families: ponericin G, W, and L. Ponericins share high sequence similarities with known peptides: ponericins G with cecropin-like peptides, ponericins W with gaegurins and melittin, and ponericins L with dermaseptins. Ten peptides were synthesized for further analysis. Their antimicrobial activities against Gram-positive and Gram-negative bacteria strains were analyzed together with their insecticidal activities against cricket larvae and their hemolytic activities. Interestingly, within each of the three families, several peptides present differences in their biological activities. The comparison of the structural features of ponericins with those of well-studied peptides suggests that the ponericins may adopt an amphipathic ␣-helical structure in polar environments, such as cell membranes. In the venom, the estimated peptide concentrations appear to be compatible with an antibacterial activity in vivo. This suggests that in the ant colony,

From individual to collective immunity: The role of the venom as antimicrobial agent in the Stenogastrinae wasp societies

“…The evidence that venom acts against bacteria and yeasts proves also that this secretion, present in conspicuous amounts on the cuticle, constitutes an antiseptic tool used by hover wasps as primary barrier to infections. This peculiar use of the venom, as already described for other arthropods, represents a clear investment in individual immunity (Torres-Larios et al, 2000;Orivel et al, 2001;Turillazzi et al, 2006;Lambardi et al, 2007;Graystock and Hughes, 2011). Moreover, the investment of an hover wasp, insofar as social, in a individual immunity may raise a form of the so called ''herd immunity'' by reducing the risk of infection for neighbouring susceptible individuals (Frank, 1998).…”

“…In ants, the metapleural gland produces secretions with antiseptic and antifungal activity (Hölldobler and Wilson, 1990) while termites secrete strong antimicrobial compounds from their faecal pellets or from soldier frontal glands (Chen et al, 1998;Rosengaus et al, 2000). Venom glands of various ants, wasps and bees produce several compounds with antimicrobial activity (Park et al, 1995;Orivel et al, 2001;Storey et al, 1991;Turillazzi, 2006) representing one of the most important source of antimicrobial substances in social Hymenoptera (Kuhn-Nentwig, 2003). In some cases, the use of venom is beyond the classical stereotype of defence against predators and can be considered as a component of the social immunity (Cremer et al, 2007;Wilson-Rich et al, 2009;Baracchi et al, 2011).…”

Dominulin A and B: Two new antibacterial peptides identified on the cuticle and in the venom of the social paper waspPolistes dominulususing MALDI-TOF, MALDI-TOF/TOF, and ESI-ion trap

“…Venom antimicrobial activity has already been reported in ants [13][14][15], and social wasps [16 -20]. In general, however, the antiseptic exocrine secretions described so far are generally of non-proteic nature [1, 21 and literature cited therein].…”

An amphibian antimicrobial peptide variant expressed in Nicotiana tabacum confers resistance to phytopathogens

“…We suppose that this property is conferred to the plant by Esc28L expression but so far we have no indication on the mechanism of action. Recently, from the ant Pachycondyla goeldii a peptide family, the ponericins, was isolated [29], displaying antimicrobial, insecticidal or haemolytic properties. A 26 % sequence identity and 70 % sequence similarity were found between Esc28L and ponericin G1 in the region 18-46 of the former molecule ( Figure 10B).…”