title: Poneratoxin, a neurotoxin from ant venom. Structure and expression in insect cells and construction of a bio-insecticide.
abstract: Poneratoxin is a small neuropeptide found in the venom of the ant Paraponera clavata. It is stored in the venom reservoir as an inactive 25-residue peptide. Here we describe both chemically synthesized poneratoxin and poneratoxin obtained by expression in insect cells. When expressed in insect cells, poneratoxin was observed attached to cell membranes. Both synthetic and recombinant ponerotoxins were soluble below pH 4.5. The structure of synthetic poneratoxin was characterized by circular dichroism and solved by nuclear magnetic resonance. In an environment imitating a lipid bilayer, at pH within the range of insect hemolymph, synthetic poneratoxin has a V shape, with two alpha-helices connected by a beta-turn. Insect larvae were paralyzed by injection of either of the purified toxins, with the recombinant one acting faster. The recombinant toxin-producing baculovirus reduced the average survival time of the insect host by 25 h compared with unmodified virus. Mass spectrometry analysis showed that the recombinant toxin has an N-terminal 21-residue extension, possibly improving its stability and/or stabilizing the membrane-bound state. The potential use of poneratoxin for the construction of biological insecticide is discussed.
authors.affiliation: Institute of Biochemistry and Biophysics (IBB), Polish Academy of Sciences, Warsaw, Poland.
authors.forename: Ewa
authors.initials: E
authors.lastname: Szolajska
authors.forename: Jaroslaw
authors.initials: J
authors.lastname: Poznanski
authors.forename: Miguel López
authors.initials: ML
authors.lastname: Ferber
authors.forename: Joanna
authors.initials: J
authors.lastname: Michalik
authors.forename: Evelyne
authors.initials: E
authors.lastname: Gout
authors.forename: Pascal
authors.initials: P
authors.lastname: Fender
authors.forename: Isabelle
authors.initials: I
authors.lastname: Bailly
authors.forename: Bernard
authors.initials: B
authors.lastname: Dublet
authors.forename: Jadwiga
authors.initials: J
authors.lastname: Chroboczek
mesh_terms: D000818:Animals; D000862:Ant Venoms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D016367:Baculoviridae / Q000235:genetics; D002460:Cell Line; D002942:Circular Dichroism; D019476:Insect Proteins; D007306:Insecticides / Q000737:chemistry / Q000378:metabolism; D008958:Models, Molecular; D009479:Neuropeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000633:toxicity; D009498:Neurotoxins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000633:toxicity; D019906:Nuclear Magnetic Resonance, Biomolecular; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D018411:Spodoptera / Q000166:cytology / Q000378:metabolism
chemical_list: D000862:Ant Venoms; D019476:Insect Proteins; D007306:Insecticides; D009479:Neuropeptides; D009498:Neurotoxins; D011994:Recombinant Proteins; C072588:poneratoxin