Membrane Proteins of Aedes aegypti Larvae Bind Toxins Cry4B and Cry11A of Bacillus thuringiensis ssp. israelensis

I. V. Krieger, L. P. Revina, L. I. Kostina, A. A. Buzdin, I. A. Zalunin^*, G. G. Chestukhina, and V. M. Stepanov

Institute of Genetics and Selection of Industrial Microorganisms, 1-yi Dorozhnyi Proezd 1, Moscow, 113545 Russia; fax: (7-095) 315-0501; E-mail: lab11@vnigen.msk.su

^* To whom correspondence should be addressed.

Received March 11, 1999; Revision received April 27, 1999

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Proteins of molecular weight 65 and 62 kD and having affinity for toxins Cry4B and Cry11A produced by Bacillus thuringiensis ssp. israelensis have been isolated from brush border membranes of Aedes aegypti larvae using affinity chromatography. Using a ligand blotting technique, we show that the binding of these proteins to the biotinylated toxins is reversible and that the two toxins compete for binding to the two proteins. These proteins are likely to be Cry4B and Cry11A toxin receptors in gut epithelial cells of Aedes aegypti larvae.

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KEY WORDS: delta-endotoxins, Bacillus thuringiensis, receptors, affinity chromatography

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