Received: June 2, 2005, Accepted: December 12, 2005, Published online: May 31, 2006.

CHARACTERIZATION OF INSECTICIDAL PEPTIDES FROM VENOM OF AUSTRALIAN FUNNEL-WEB SPIDERS

VONARX E. J. (1), TYLER M. I. (2), ATKINSON R. K. (3), HOWDEN M. E. H. (1)

(1) School of Biological and Chemical Sciences, Deakin University, Geelong, Victoria, Australia; (2) Australian Proteome Analysis Facility, Macquarie University, Sydney, New South Wales, Australia; (3) School of Applied Science, University of Southern Queensland, Toowoomba, Queensland, Australia.

ABSTRACT: Australian funnel-web spiders are relatively large primitive hunting spiders. Male Atrax robustus spiders have been responsible for a number of human deaths. Venom was collected from the species Hadronyche infensa (Hickman) [female], H. formidabilis [male and female], H. versuta [female], and A. robustus (Cambridge) [male] and was fractionated by high performance liquid chromatography. This resulted in the isolation and purification of a homologous series of 7 insecticidal peptides of relatively low molecular mass (approximately 4kDa). The amino acid sequences of these toxins consisted of 36 or 37 amino acids and were named atracotoxins. For the major bioassay of these toxins, we used the cotton bollworm, Helicoverpa armigera (Hubner), due to the great damage it causes to crops worldwide. These toxins, when injected subcutaneously into fifth or sixth instar larvae of Helicoverpa armigera, were lethal or caused an apparently irreversible writhing. The toxin from H. versuta venom showed no significant toxicity when subcutaneously injected into newborn mice. One of the toxins was found to have a free acid carboxyl terminus. These toxins have great potential as lead compounds for insecticide design or for incorporation in recombinant baculovirus insecticides.

KEY WORDS: Australian funnel-web spiders, Hadronyche and Atrax species, venom, insecticidal toxins, peptides, Helicoverpa armigera.

CORRESPONDENCE TO:

MERLIN HOWDEN, 297 Halcrows Road, Glenorie, 2157, Sydney, New South Wales, Australia. Phone: + 61 2 9652 1238. Fax: + 61 2 9652 0046. Email: m.howden@unsw.edu.au.