Toxicity of Protease-Resistant Domains from the Delta-Endotoxin of Bacillus thuringiensis subsp. israelensis in Culex quinquefasciatus and Aedes aegypti Bioassays

Authors

Mary Ann Pfannenstiel, University of Nebraska-Lincoln
William C. Cray Jr., University of Nebraska-Lincoln
Graham Couche, University of Nebraska-Lincoln
Kenneth W. Nickerson, University of Nebraska-LincolnFollow

Date of this Version

January 1990

Comments

Published in APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Jan. 1990, p. 162-166 Vol. 56, No. 1. Copyright 1990, American Society for Microbiology. Used by permission.

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.