Insect- and vertebrate-selective neurotoxins from Australian urodacid and buthid scorpion venoms : lead compounds for novel biopesticides

Wilson, HL

Insect- and vertebrate-selective neurotoxins from Australian urodacid and buthid scorpion venoms : lead compounds for novel biopesticides

Wilson, HL

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Publication Type:: Thesis
Issue Date:: 2003

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Field	Value	Language
dc.contributor.author	Wilson, HL
dc.date.accessioned	2014-11-23T20:37:18Z
dc.date.available	2014-11-23T20:37:18Z
dc.date.issued	2003
dc.identifier.uri	http://hdl.handle.net/10453/30241
dc.description	University of Technology, Sydney. Department of Health Sciences.	en_US
dc.description.abstract	Scorpions from nine species were collected from locations across Australia comprising four Lychas (Buthidae), four Urodacus (Urodacidae) and one Cercophonius (Bothriuridae) . Three species had not been described previously. Lychas and Urodacus species collected in sufficient numbers were milked regularly for their venom, and characteristics of the venom determined. Insect toxicity was qualitatively demonstrated for two Lychas species. Insect and vertebrate toxicity was determined for Urodacus manicatus and U. hoplurus, and both species were shown to have very low mammalian toxicity (>4mg/kg). Insect toxicity of these two venoms was estimated at 300-500μg/ g by injection into crickets (Acheta domesticus). Venom profiles prepared by rp-HPLC revealed that Lychas venom was simple in composition and resembles that seen in overseas buthids. Venom composition of the Urodacus species was extremely complex, complicating attempts to purify individual proteins. Toxins were purified from the venom by rp-HPLC or size-exclusion chromatography (SEC) followed by HPLC, and screened for activity in vertebrate (chick biventer cervicis) and insect bioassays. Fractions from both species showed selective excitatory toxicity towards insects and / or vertebrates. Effects on vertebrate muscle included contracture and increased stimulated twitch tension, and some fractions produced fasciculation. Further investigation was undertaken to determine the effects on ion channels in insects, as part of a search for potential biopesticide compounds. In neurones isolated from the American cockroach terminal abdominal ganglion, the predominant effect was a block of whole-cell sodium current.	en_US
dc.format	Thesis (PhD)	en_US
dc.language.iso	en	en_US
dc.relation	https://opus.lib.uts.edu.au/bitstream/10453/30241/8/02Whole.pdf
dc.rights	info:eu-repo/semantics/openAccess
dc.rights	The author owns the copyright in this thesis including all reproduction and reuse rights for the work. The work may not be altered without the permission of the copyright owner. Attribution is essential when quoting or paraphrasing from this thesis.
dc.rights	au.edu.uts.lib/ppc
dc.rights	© 2003 Harry Wilson
dc.subject	Scorpions.	en
dc.subject	Venom.	en
dc.subject	Biopesticides.	en
dc.subject	Australia.	en
dc.title	Insect- and vertebrate-selective neurotoxins from Australian urodacid and buthid scorpion venoms : lead compounds for novel biopesticides	en_US
dc.type	Thesis
utslib.copyright.status	open_access

Abstract:

Scorpions from nine species were collected from locations across Australia comprising four Lychas (Buthidae), four Urodacus (Urodacidae) and one Cercophonius (Bothriuridae) . Three species had not been described previously. Lychas and Urodacus species collected in sufficient numbers were milked regularly for their venom, and characteristics of the venom determined. Insect toxicity was qualitatively demonstrated for two Lychas species. Insect and vertebrate toxicity was determined for Urodacus manicatus and U. hoplurus, and both species were shown to have very low mammalian toxicity (>4mg/kg). Insect toxicity of these two venoms was estimated at 300-500μg/ g by injection into crickets (Acheta domesticus). Venom profiles prepared by rp-HPLC revealed that Lychas venom was simple in composition and resembles that seen in overseas buthids. Venom composition of the Urodacus species was extremely complex, complicating attempts to purify individual proteins. Toxins were purified from the venom by rp-HPLC or size-exclusion chromatography (SEC) followed by HPLC, and screened for activity in vertebrate (chick biventer cervicis) and insect bioassays. Fractions from both species showed selective excitatory toxicity towards insects and / or vertebrates. Effects on vertebrate muscle included contracture and increased stimulated twitch tension, and some fractions produced fasciculation. Further investigation was undertaken to determine the effects on ion channels in insects, as part of a search for potential biopesticide compounds. In neurones isolated from the American cockroach terminal abdominal ganglion, the predominant effect was a block of whole-cell sodium current.

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http://hdl.handle.net/10453/30241