1axh

Publication Abstract from PubMed

A family of potent insecticidal toxins has recently been isolated from the venom of Australian funnel web spiders. Among these is the 37-residue peptide omega-atracotoxin-HV1 (omega-ACTX-HV1) from Hadronyche versuta. We have chemically synthesized and folded omega-ACTX-HV1, shown that it is neurotoxic, ascertained its disulphide bonding pattern, and determined its three-dimensional solution structure using NMR spectroscopy. The structure consists of a solvent-accessible beta-hairpin protruding from a disulphide-bonded globular core comprising four beta-turns. The three intramolecular disulphide bonds from a cystine knot motif similar to that seen in several other neurotoxic peptides. Despite limited sequence identity, omega-ACTX-HV1 displays significant structural homology with the omega-agatoxins and omega-conotoxins, both of which are vertebrate calcium channel antagonists; however, in contrast with these toxins, we show that omega-ACTX-HV1 inhibits insect, but not mammalian, voltage-gated calcium channel currents.

The structure of a novel insecticidal neurotoxin, omega-atracotoxin-HV1, from the venom of an Australian funnel web spider.,Fletcher JI, Smith R, O'Donoghue SI, Nilges M, Connor M, Howden ME, Christie MJ, King GF Nat Struct Biol. 1997 Jul;4(7):559-66. PMID:9228949^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.