title: Stability of the larvicidal activity of Bacillus thuringiensis subsp. israelensis: amino acid modification and denaturants.
abstract: The Bacillus thuringiensis subsp. israelensis mosquito larvicidal toxin is not a sulfhydryl-activated toxin. The protein disulfide bonds were cleaved and blocked without loss of toxicity. In contrast, modification of the lysine side chains eliminated toxicity. Additionally, the toxin was resistant to high concentrations of salt (8 M NaBr), organic solvents (40% methanol), denaturants (4 M urea), and neutral detergents (10% Triton X-100). However, it was inactivated by both positively and negatively charged detergents and by guanidine hydrochloride.
authors.forename: M A
authors.initials: MA
authors.lastname: Pfannenstiel
authors.forename: G A
authors.initials: GA
authors.lastname: Couche
authors.forename: G
authors.initials: G
authors.lastname: Muthukumar
authors.forename: K W
authors.initials: KW
authors.lastname: Nickerson
mesh_terms: D000818:Animals; D001413:Bacillus thuringiensis; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000302:isolation & purification / Q000378:metabolism; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000378:metabolism; D009033:Culicidae; D003902:Detergents; D004220:Disulfides / Q000032:analysis; D004355:Drug Stability; D004731:Endotoxins; D006460:Hemolysin Proteins; D007814:Larva; D008239:Lysine; D011485:Protein Binding; D011489:Protein Denaturation; D012997:Solvents; D013439:Sulfhydryl Reagents / Q000494:pharmacology
chemical_list: D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; D003902:Detergents; D004220:Disulfides; D004731:Endotoxins; D006460:Hemolysin Proteins; D012997:Solvents; D013439:Sulfhydryl Reagents; C030956:insecticidal crystal protein, Bacillus Thuringiensis; C045759:larval toxin, Bacillus; D008239:Lysine