In silico identification of cross affinity towards Cry1Ac pesticidal protein with receptor enzyme in Bos taurus and sequence, structure analysis of crystal proteins for stability

Abstract

Any novel protein introduced into the GM crops need to be evaluated for cross affinity on living organisms. Many researchers are currently focusing on the impact of Bacillus thuringiensis cotton on soil and microbial diversity by field experiments. In spite of this, in silico approach might be helpful to elucidate the impact of cry genes. The crystal a protein which was produced by Bt at the time of sporulation has been used as a biological pesticide to target the insectivorous pests like Cry1Ac for Helicoverpa armigera and Cry2Ab for Spodoptera sp. and Heliothis sp. Here, we present the comprehensive in silico analysis of Cry1Ac and Cry2Ab proteins with available in silico tools, databases and docking servers. Molecular docking of Cry1Ac with procarboxypeptidase from Helicoverpa armigera and Cry1Ac with Leucine aminopeptidase from Bos taurus has showed the 125th amino acid position to be the preference site of Cry1Ac protein. The structures were compared with each other and it showed 5% of similarity. The cross affinity of this toxin that have confirmed the earlier reports of ill effects of Bt cotton consumed by cattle.

Structural classification of insecticidal proteins – Towards an in silico characterisation of novel toxins

“…Without a detailed understanding of which interactions are crucial for toxicity, such studies are likely to throw up many false positives, indeed one report predicts that Cry1Ac could have activity against cattle (Ebenezer et al, 2013), a prediction that is not supported by experimental observations. In summary, whilst our understanding of toxin structure is rapidly progressing, and might suggest that the large family of toxins is less diverse than was thought, we are still a long way from the goal of being able to match toxins and hosts based on primary sequence data generated from genome sequencing.…”