Stability of the Larvicidal Activity of Bacillus thuringiensis subsp. israelensis: Amino Acid Modification and Denaturants

Authors

Mary Ann Pfannenstiel, University of Nebraska-Lincoln
Graham A. Couche, University of Nebraska-Lincoln
Ganapathy Muthukumar, University of Nebraska-Lincoln
Kenneth Nickerson, University of Nebraska-LincolnFollow

Date of this Version

11-1-1985

Comments

Published in APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Nov. 1985, p. 1196-1199 Vol. 50, No. 5. Copyright 1985, American Society for Microbiology. Used by permission.

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.