کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2008447 | 1066413 | 2008 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: The pre-pore from Bacillus thuringiensis Cry1Ab toxin is necessary to induce insect death in Manduca sexta The pre-pore from Bacillus thuringiensis Cry1Ab toxin is necessary to induce insect death in Manduca sexta](/preview/png/2008447.png)
The insecticidal Cry toxins from Bacillus thuringiensis bacteria are pore-forming toxins that lyse midgut epithelial cells in insects. We have previously proposed that they form pre-pore oligomeric intermediates before membrane insertion. For formation of these oligomers coiled-coil structures are important, and helix α-3 from Cry toxins could form coiled-coils. Our data shows that different mutations in helix α-3 are affected in pore formation and toxicity. Mutants affected in toxicity bind Bt-R1 receptor with a similar KD as the wild type toxin but do not form oligomers nor induce pore formation in planar lipid bilayers, indicating that the pre-pore oligomer is an obligate intermediate in the intoxication of Cry1Ab toxin and that interaction of monomeric Cry1Ab with Bt-R1 is not enough to kill susceptible larvae.
Journal: Peptides - Volume 29, Issue 2, February 2008, Pages 318–323