Loop residues of the receptor binding domain of Bacillus thuringiensis Cry11Ba toxin are important for mosquitocidal activity.
Using a Cry11Ba toxin model, predicted loops in domain II were analyzed for their role in receptor binding and toxicity. Peptides corresponding to loops alpha8, 1 and 3, but not loop 2, competed with toxin binding to Aedes midgut membranes. Mutagenesis data reveal loops alpha8, 1 and 3 are involved in toxicity. Loops 1 and 3 are of greater significance in toxicity to Aedes and Culex larvae than to Anopheles. Cry11Ba binds the apical membrane of larval caecae and posterior midgut, and binding can be competed by loop 1 but not by loop 2 peptides. Cry11Ba binds the same regions to which anti-cadherin antibody binds, and this antibody competes with Cry11Ba binding suggesting a possible role of cadherin in toxication.
Likitvivatanavong
Supaporn
S
Department of Cell Biology and Neuroscience, University of California, Riverside, CA 92521, USA.
Aimanova
Karlygash G
KG
Gill
Sarjeet S
SS
D000330:Aedes; D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles; D001413:Bacillus thuringiensis / Q000235:genetics / Q000502:physiology*; D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D001427:Bacterial Toxins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000633:toxicity; D001665:Binding Sites; D001667:Binding, Competitive; D003465:Culex; D004064:Digestive System / Q000378:metabolism; D004731:Endotoxins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D006460:Hemolysin Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism / Q000633:toxicity*; D007814:Larva / Q000378:metabolism; D008871:Microvilli / Q000378:metabolism; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D010572:Pest Control, Biological; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000633:toxicity; D017386:Sequence Homology, Amino Acid
D000083722:Bacillus thuringiensis Toxins; D001426:Bacterial Proteins; D001427:Bacterial Toxins; C115468:CRY11BB protein, Bacillus thuringiensis; D004731:Endotoxins; D006460:Hemolysin Proteins; D011994:Recombinant Proteins; C030956:insecticidal crystal protein, Bacillus Thuringiensis