6533b7d9fe1ef96bd126bfc1

RESEARCH PRODUCT

Occurrence of three different binding sites forBacillus thuringiensisδ-endotoxins in the midgut brush border membrane of the potato tuber moth,phthorimaea operculella(zeller)

M. Dolores RealAmparo C. Martínez-ramírezBaltasar EscricheFrancisco J. SilvaJuan Ferré

subject

education.field_of_studyintegumentary systemBrush borderPhysiologymusculoskeletal neural and ocular physiologyfungiPopulationMidgutGeneral MedicineBiologybiology.organism_classificationBiochemistryBacillaleshumanitiesPhthorimaea operculellaBiochemistryInsect ScienceBacillus thuringiensisBiotinylationBinding siteeducation

description

The potato tuber moth is susceptible to at least three insecticidal crystal proteins (ICPs) from Bacillus thuringiensis: CrylA(b), CrylB, and CrylC. To design useful combinations of toxin genes either in transgenic plants or in new genetically modified B. thuringiensis strains, it is necessary to determine the binding characteristics of the different ICPs so as not to combine a pair sharing the same binding site. This has been accomplished using two different techniques: 125I-labeling of the ICPs with further measurement of the radioactivity bound to brush border membrane vesicles, and microscopic visualization of the bound ICPs by enzyme-linked reagents such as antibodies or streptavidin using biotinylated ICPs. Our results show that CrylA(b), CrylB, and CrylC bind to different sites in the brush border membrane of midgut epithelial cells. Also, the affinity of the binding sites for the ICPs and their concentration in brush border membrane vesicles has been determined in a laboratory strain and a storage collected population. No significant differences were found between these two strains. © 1994 Wiley-Liss, Inc.

https://doi.org/10.1002/arch.940260407