Comprehensive in silico allergenicity assessment of novel protein engineered chimeric Cry proteins for safe deployment in crops.

Authors:
Maniraj Rathinam
Maniraj Rathinam
ICAR-National Research Centre on Plant Biotechnology
New Delhi | India
Shweta Singh
Shweta Singh
Institute of Liver and Biliary Sciences
United Kingdom
Debasis Pattanayak
Debasis Pattanayak
ICAR-National Research Centre on Plant Biotechnology
New Delhi | India
Rohini Sreevathsa
Rohini Sreevathsa
Indian Agricultural Research Institute
India

BMC Biotechnol 2017 Aug 2;17(1):64. Epub 2017 Aug 2.

ICAR-National Research Centre on Plant Biotechnology, LBS Centre, Pusa Campus, New Delhi, 110012, India.

Background: Development of chimeric Cry toxins by protein engineering of known and validated proteins is imperative for enhancing the efficacy and broadening the insecticidal spectrum of these genes. Expression of novel Cry proteins in food crops has however created apprehensions with respect to the safety aspects. To clarify this, premarket evaluation consisting of an array of analyses to evaluate the unintended effects is a prerequisite to provide safety assurance to the consumers. Additionally, series of bioinformatic tools as in silico aids are being used to evaluate the likely allergenic reaction of the proteins based on sequence and epitope similarity with known allergens.

Results: In the present study, chimeric Cry toxins developed through protein engineering were evaluated for allergenic potential using various in silico algorithms. Major emphasis was on the validation of allergenic potential on three aspects of paramount significance viz., sequence-based homology between allergenic proteins, validation of conformational epitopes towards identification of food allergens and physico-chemical properties of amino acids. Additionally, in vitro analysis pertaining to heat stability of two of the eight chimeric proteins and pepsin digestibility further demonstrated the non-allergenic potential of these chimeric toxins.

Conclusions: The study revealed for the first time an all-encompassing evaluation that the recombinant Cry proteins did not show any potential similarity with any known allergens with respect to the parameters generally considered for a protein to be designated as an allergen. These novel chimeric proteins hence can be considered safe to be introgressed into plants.

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http://dx.doi.org/10.1186/s12896-017-0384-zDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5541426PMC
August 2017
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