A pain-causing and paralytic ant venom glycopeptide

Abstract

Summary Ants (Hymenoptera: Formicidae) are familiar inhabitants of most terrestrial environments. Although we are aware of the ability of many species to sting, knowledge of ant venom chemistry remains limited. Herein, we describe the discovery and characterization of an O -linked glycopeptide (Mg7a) as a major component of the venom of the ant Myrmecia gulosa . Electron transfer dissociation and higher-energy collisional dissociation tandem mass spectrometry were used to localize three α- N -acetylgalactosaminyl residues (α-GalNAc) present on the 63-residue peptide. To allow for functional studies, we synthesized the full-length glycosylated peptide via solid-phase peptide synthesis, combined with diselenide–selenoester ligation-deselenization chemistry. We show that Mg7a is paralytic and lethal to insects, and triggers pain behavior and inflammation in mammals, which it achieves through a membrane-targeting mode of action. Deglycosylation of Mg7a renders it insoluble in aqueous solution, suggesting a key solubilizing role of the O -glycans.

Total Chemical Synthesis of Correctly Folded Disulfide-Rich Proteins Using a Removable O-Linked β-N-Acetylglucosamine Strategy

“…Thus, the RGM-assisted protein folding strategy has an additional advantage in chemical protein synthesis, namely, improvement of the handling properties of the reaction intermediates. Recent studies also showed that O-GalNAc plays a critical role in maintaining the aqueous solubility of peptides as well …”

“…Recent studies also showed that O-GalNAc plays a critical role in maintaining the aqueous solubility of peptides as well. 58 Next, the folding of monomer 15 was performed by gradient dialysis at 4 °C. First, 2.0 mg of 15 was dissolved in 0.95 mL of denaturing buffer (150 μM, 6 M Gn•HCl, 100 mM Tris, 1 mM GSH, 100 μM GSSG, pH 7.4), and the mixture was centrifuged.…”

The mechanism underlying toxicity of a venom peptide against insects reveals how ants are master at disrupting membranes

“…Proteo-transcriptomic investigations conducted on a panel of Hymenoptera now allow us to appreciate the full complexity of venoms and will accelerate the delineation of the biological activity of venom peptides. In particular, the analysis of ant, wasp, or velvet ant venoms, coupled with functional assays, has already identified several new insecticidal, 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 antimicrobial, 10 , 11 , 18 , 19 , 20 , 21 , 22 anthelminthic 15 , 23 , 24 and pain-causing 10 , 25 , 26 , 27 peptides. These studies led to the description of the hyperdiverse peptide gene superfamily, called aculeatoxins, which appears to be widespread in Hymenoptera particularly in ant venoms.…”

Proteinaceous Venom Expression of the Yellow Meadow Ant, Lasius flavus (Hymenoptera: Formicidae)

“…The venom of ants derived from venom glands can be used in predating, defense, or offense, but also serve as chemical communication [ 4 , 5 ]. Ant venom is composed of a mixture of peptides, proteins, and other chemicals, such as formic acid, biogenic amines, and alkaloids, exhibiting diverse activities, such as insecticidal, antimicrobial, and antinociceptive activities [ 6 , 7 ]. It is a promising resource of novel bioactive molecules that can be used for biopesticides and drug development [ 8 ].…”