Membrane proteins of Aedes aegypti larvae bind toxins Cry4B and Cry11A of Bacillus thuringiensis ssp israelensis

Proteins of molecular weight 65 and 62 kD and having affinity for toxins Cr y4B and Cry11A produced by Bacillus thuringiensis ssp. israelensis have bee n isolated from brush border membranes of Aedes aegypti larvae using affini ty chromatography. Using a ligand blotting technique, we show that the: bin ding of these proteins to the biotinylated toxins is reversible and that th e two toxins compete for binding to the two proteins. These proteins are li kely to be Cry4B and Cry11A toxin receptors in gut epithelial cells of Aede s aegypti larvae.