Identification of scFv Molecules that Recognize Loop 3 of Domain II and Domain III of Cry1Ab Toxin from Bacillus thuringiensis
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چکیده
A phage repertoire was constructed using antibody genes from the bone marrow and the spleen of a rabbit immunized with Cry1Ab toxin. Biopanning against either the Cry1Ab toxin or a domain II loop 3 synthetic peptide resulted in the identification of monoclonal antibodies in scFv format. They inhibited binding and toxicity of Cry1Ab toxin against Manduca sexta. Toxin overlay assays, using the scFv antibodies as competitors, revealed that the anti-loop 3 molecule competed with Cry1Ab toxin binding to the cadherin receptor (Bt-R1) of M. sexta, while anti-domain III antibodies interfered with the binding of Cry1Ab toxin to the aminopeptidase N (APN) receptor of this insect.
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