Molecular and structural characterization of a novel Cry1D toxin from Bacillus thuringiensis with high toxicity to Spodoptera littoralis (Lepidoptera: Noctuidae)
| Autor: | Dalel BenFarhat-Touzri, Fatma Driss, Sonia Jemli, Slim Tounsi |
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| Rok vydání: | 2019 |
| Předmět: |
Models
Molecular Insecticides Bacillus thuringiensis 02 engineering and technology Spodoptera medicine.disease_cause Biochemistry Hemolysin Proteins 03 medical and health sciences Bacterial Proteins Western blot Structural Biology Toxicity Tests Escherichia coli medicine Animals Amino Acid Sequence Spodoptera littoralis Molecular Biology Phylogeny 030304 developmental biology 0303 health sciences Bacillus thuringiensis Toxins biology medicine.diagnostic_test Molecular mass Chemistry Toxin Midgut Sequence Analysis DNA General Medicine 021001 nanoscience & nanotechnology biology.organism_classification Endotoxins Open reading frame Gene Expression Regulation Noctuidae 0210 nano-technology |
| Zdroj: | International Journal of Biological Macromolecules. 126:969-976 |
| ISSN: | 0141-8130 |
| Popis: | The investigation of new Bacillus thuringiensis (Bt) insecticidal proteins (Cry) with specific toxicity is one of the alternative measures used for Lepidopteran pest control. In the present study, a new Cry toxin was identified from a promising Bt strain BLB250 which was previously selected for its high toxicity against Spodoptera littoralis. The corresponding gene, designated cry1D-250, was cloned. It showed an ORF of 3498 bp, encoding a protein of 1165 amino acid residues with a putative molecular mass of 132 kDa which was confirmed by SDS-PAGE and Western blot analyses. The corresponding toxin named Cry1D-250 showed a higher insecticidal activity towards S. littoralis than Cry1D-133 (LC50 of 224.4 ng cm−2) with an LC50 of only 166 ng cm−2. Besides to the 65 kDa active toxin, proteolysis activation of Cry1D-133 protein with S. littoralis midgut juice generated an extra form of 56 kDa, which was the result of a second cleavage. Via activation study and 3D structure analysis, novel substitutions found in the Cry1D-250 protein compared to Cry1D-133 toxin were shown to be involved in the protein stability and toxicity. Therefore, the Cry1D-250 toxin can be considered to be an effective alternative for the control of S. littoralis. |
| Databáze: | OpenAIRE |
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