Browse by author
Lookup NU author(s): Dr Debra Patten
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
A new insecticidal toxin Tx4(5-5) was isolated from the fraction PhTx4 of the venom of the spider Phoneutria nigriventer by reverse phase high performance liquid chromatography (HPLC) and anion exchange HPLC. The complete amino acid sequence determined by automated Edman degradation showed that Tx4(5-5) is a single chain polypeptide composed of 47 amino acid residues, including 10 cysteines, with a calculated molecular mass of 5175 Da. Tx4(5-5) shows 64% of sequence identity with Tx4(6-1), another insecticidal toxin from the same venom. Tx4(5-5) was highly toxic to house fly (Musca domestica), cockroach (Periplaneta americana) and cricket (Acheta domesticus ), producing neurotoxic effects (knock-down, trembling with unco-ordinated movements) at doses as low as 50 ng/g (house fly), 250 ng/g (cockroach) and 150 ng/g (cricket). In contrast, intracerebroventricular injections (30 μg) into mice induced no behavioural effects. Preliminary electrophysiological studies carried out on whole-cell voltage-clamped rat hippocampal neurones indicated that Tx4(5-5) (at 1 μ M) reversibly inhibited the N-methyl- -aspartate-subtype of ionotropic glutamate receptor, while having little or no effect on kainate-, α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid- or γ-aminobutyric acid-activated currents.
Author(s): de Figueiredo SG, de Lima ME, Nascimento Cordeiro M, Diniz CR, Patten D, Halliwell RF, Gilroy J, Richardson M
Publication type: Article
Publication status: Published
Journal: Toxicon
Year: 2001
Volume: 39
Issue: 2-3
Pages: 309-317
ISSN (print): 0041-0101
ISSN (electronic): 1879-3150
Publisher: Pergamon
URL: http://dx.doi.org/10.1016/S0041-0101(00)00129-X
DOI: 10.1016/S0041-0101(00)00129-X
Altmetrics provided by Altmetric
