Fluorescent analyses of Bacillus thuringiensis Cry1Fa and Cry1Ab toxin binding sites on brush border membrane vesicles of Ostrinia nubilalis (Hübner), Diatraea grandiosella (Dyar), and Helicoverpa zea (Boddie) larvae
| Autor: | Michael J. Adang, Qi Zhang, Gang Hua, Reben Raeman |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
0301 basic medicine European corn borer Health Toxicology and Mutagenesis Bacillus thuringiensis Context (language use) Moths 01 natural sciences Zea mays Ostrinia Diatraea 03 medical and health sciences Hemolysin Proteins Bacterial Proteins Animals Binding site Binding Sites biology Microvilli Ligand binding assay fungi food and beverages General Medicine biology.organism_classification Endotoxins 010602 entomology 030104 developmental biology Biochemistry Larva Helicoverpa zea Agronomy and Crop Science |
| Zdroj: | Pesticide biochemistry and physiology. 167 |
| ISSN: | 1095-9939 |
| Popis: | Bacillus thuringiensis (Bt) Cry1Fa and Cry1Ab proteins are important Cry toxins due to their high, selective toxicity against a number of lepidopteran species, including important pests of corn and cotton. Competition binding assays are a classical tool for investigating Cry toxin interactions with target pest insects. We developed a fluorescence-based binding assay and assessed Cry1Fa and Cry1Ab toxin binding to brush border membrane preparations from lepidopteran corn pests including Ostrinia nubilalis (European corn borer, ECB), Diatraea grandiosella (south western corn borer, SWCB), and Helicoverpa zea (corn earworm, CEW). Homologous and heterologous competition binding assays with fluorophore-(Alexa488)-labeled Cry1Fa toxin showed that Cry1Fa shares binding site(s) with Cry1Ab toxin in ECB, and SWCB for which Cry1Ab has higher affinity than Cry1Fa. Apart from the shared binding sites, Cry1Ab and Cry1Fa bind an additional site(s) in ECB and SWCB. In CEW, Cry1Fa and Cry1Ab each, has a high affinity binding site(s), which binds the heterologous toxin with low affinity. The Cry1Ab-Cry1Fa toxin binding models for ECB, SWCB and CEW based on our results are considered in the context of what is known about acquired cross-resistance against Cry1Ab and Cry1Fa toxins. |
| Databáze: | OpenAIRE |
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