title: Toxicity of protease-resistant domains from the delta-endotoxin of Bacillus thuringiensis subsp. israelensis in Culex quinquefasciatus and Aedes aegypti bioassays.
abstract: The mosquitocidal glycoprotein endotoxin of Bacillus thuringiensis subsp. israelensis was digested with chymotrypsin to yield protease-resistant domains which were then separated from smaller protease digestion products by high-performance liquid chromatography. Once purified, the domains no longer bound wheat germ agglutinin, a lectin which binds N-acetylglucosamine (GlcNAc) and GlcNAc oligomers. Purified protease-resistant domains were as toxic for Culex quinquefasciatus larvae as intact solubilized toxin. In separate experiments, the toxicity of chymotrypsin-digested endotoxin for Aedes aegypti larvae was reduced fivefold or more. A model is presented in which GlcNAc-containing oligosaccharides are required for toxicity for A. aegypti larvae but not C. quinquefasciatus larvae.
authors.affiliation: School of Biological Sciences, University of Nebraska, Lincoln 68588-0343.
authors.forename: M A
authors.initials: MA
authors.lastname: Pfannenstiel
authors.forename: W C
authors.initials: WC
authors.lastname: Cray
authors.forename: G A
authors.initials: GA
authors.lastname: Couche
authors.forename: K W
authors.initials: KW
authors.lastname: Nickerson
mesh_terms: D000330:Aedes; D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D001681:Biological Assay; D002851:Chromatography, High Pressure Liquid; D002918:Chymotrypsin / Q000378:metabolism; D003465:Culex; D004591:Electrophoresis, Polyacrylamide Gel; D004731:Endotoxins / Q000378:metabolism*; D006460:Hemolysin Proteins; D007306:Insecticides / Q000378:metabolism*; D007814:Larva; D037102:Lectins / Q000378:metabolism; D010572:Pest Control, Biological
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D004731:Endotoxins; D006460:Hemolysin Proteins; D007306:Insecticides; D037102:Lectins; C030956:insecticidal crystal protein, Bacillus Thuringiensis; D002918:Chymotrypsin