An Approach to Reconfirm Transgenic “Cry” Protein Sequences as Safe for Use in Genetic Engineering by Bioinformatic Tools
DOI:
https://doi.org/10.14205/2310-6980.2014.02.01.3Keywords:
Cry proteins, Bacillus thuringiensis (Bt), Allergenicity, Bioinformatics, FASTA.Abstract
Background: Genetically engineered (GM) crops are produced by the insertion of specific genes from Bacillus thuringiensis [Bt] that encode a transgenic protein which must be evaluated for potential safety and allergenicity prior to crop development and market release.
Objective: The aim of the present work was to re inspect the allergenicity of Cry 1Ab, Cry 1Ac and Cry 1C transgenic protein sequences using FASTA based bioinformatics tools.
Methods: An in silico approach was employed to assess allergenicity and cross-reactivity of three Cry proteins- Cry 1Ab, Cry 1Ac and Cry 1C being preferred transgenic proteins of crop developers in India. A non-allergenic dietary spinach rubisco, a small subunit protein, and a known food allergen Arah 1 were analysed as per recommended criteria, using Full FASTA alignment and 80 amino acid window approach in allergen databases- FARRP and SDAP.
Results: None of the transgenic Cry 1Ab, Cry 1Ac and Cry 1C proteins showed sequence similarity of >35% with any known allergenic sequence in allergen databases. Dietary protein showed a high of only 21% similarity with Apim allergen sequence, while Arah 1, a proven food allergen reflected greater than 35% sequence similarity with known allergen such as beta-conglycin under the 80 amino acid window approach.
Conclusion: The allergenicity assessment by in silico tools of three Cry proteins, used for development of genetically engineered crops did not indicate significant alignment and similarity with any known allergen(s) in the database. This confirmed the approach for use of Cry proteins as safe transgenic proteins in genetic engineering from allergenicity point of view.
References
Taylor SL, Hefle SL. Will genetically modified foods be allergenic? J Allergy Clin Immunol 2001; 107: 765-71. http://dx.doi.org/10.1067/mai.2001.114241
Hileman RE, Silvanovich A, Goodman RE, Rice EA, Holleschak G, Astwood JD, Hefle SL. Bioinformatic methods for allergenicity assessment using a comprehensive allergen database. Int Arch Allergy Immunol 2002; 128: 280–291. http://dx.doi.org/10.1159/000063861
Goodman RE. Performing IgE serum testing due to bioinformatics matches in the allergenicity assessment of GM crops. Food Chem Toxicol 2008; 46(Suppl 10): S24-34. http://dx.doi.org/10.1016/j.fct.2008.07.023
Batista R, Nunes B, Cardoso C, Jose HS, Almeida AB, Manique A, Bento L, Ricardoc P, Oliveir M.M. Lack of detectable allergenicity of transgenic maize and soya samples. J Allergy Clin Immunol 2005; 116: 403-10. http://dx.doi.org/10.1016/j.jaci.2005.04.014
Codex Alimentarius Commission. Alinorm 03/34: Joint FAO/WHO Food Standard Programme, Codex Alimentarius Commission, Appendix III, Guideline for the conduct of food safety assessment of foods derived from recombinant DNA plants and Appendix IV, Annex on the assessment of possible allergenicity. 2003, 30 June–5 July, 25thSession. Rome. Italy. pp. 47–60. URL: http://ftp.fao.org/es/esn/food/ guide_plants_en.p.
Indian Council of Medical Research (ICMR). Indian guidelines on assessing GM crops. 2008 URL: http://www.icmr.nic.in/guide/Guidelines.
Aalberse RC. Structural biology of allergens. J Allergy Clin Immunol 2000; 106: 228–238. http://dx.doi.org/10.1067/mai.2000.108434
Food and Agriculture Organization/World Health Organization (FAO/WHO). Evaluation of the Allergenicity of Genetically Modified foods: Report of a Joint FAO/WHO Expert Consultation. 2002 22–25 January. Rome, Italy. URL: http://www.fao.org/docrep/ 007/y0820e/y0820e00.HTM.
IGMORIS. Indian GMO Research Information System, Department of Biotechnology, Govt. of India. URL: http://igmoris.nic.in/
Ivanciuc O, Schein, CH, Braun W. SDAP: database and computational tools for allergenic proteins. Nucleic Acids Res 2003; 31: 359–362. http://dx.doi.org/10.1093/nar/gkg010
Metcalfe DD, Astwood JD, Townsend R, Sampson HA, Taylor SL, Fuchs RL. Assessment of the allergenic potential of foods derived from genetically engineered crop plants. Crit Rev Food Sci Nutr 1996; 36: S165–186. http://dx.doi.org/10.1080/10408399609527763
Stadler MB, Stadler BM. Allergenicity prediction by protein sequence. FASEB J 2003; 17: 1141–1143.
Silvanovich A, Nemeth MA, Song P, Herman R, Tagliani L, Bannon GA. The value of short amino acid sequence matches for prediction of protein allertenicity. Toxicol Sci 2006; 90: 252–258. http://dx.doi.org/10.1093/toxsci/kfj068
Kleter GA, Peijnenburg AACM. Screening of transgenic proteins expressed in transgenic food crops for the presence of short amino acid sequences identical to potential, IgE – binding linear epitopes of allergens. BMC Structural Biology 2002; 2: 8. http://dx.doi.org/10.1186/1472-6807-2-8
Verma AK, Mishra A, Subash S, Das M, Dwivedi PD. Computational allergenicity prediction of transgenic proteins expressed in genetically modified crops. Immunophrmacology and Immunotoxicology 2011; 33(3): 410- 422. http://dx.doi.org/10.3109/08923973.2010.523704
Randhawa GJ, Singh M, Grover M. Bioinformatic analysis for allergenicity assessment of Bacillus thuringiensis Cry proteins expressed in insect-resistant food crops. Food and chemical Toxicology 2011; 49: (2)356–362. http://dx.doi.org/10.1016/j.fct.2010.11.008
López-Torrejón G, Salcedo G, Martin Esteban M, DíazPerales A, Pascual CY, Sánchez-Monge R. Len c 1, a major allergen and vicilin from lentil seeds: Protein isolation and cDNA cloning. J Allergy Clin Immunol 2003; 112: 1208-15. http://dx.doi.org/10.1016/j.jaci.2003.08.035
Goggin DE, Mir E, Smith WB, Stuckey M, Smith PMC. Proteomic Analysis of Lupin Seed Proteins to Identify Conglutin as an Allergen, Lup an 1. J Agri Food Chem 2008; 56: 6370-6377. http://dx.doi.org/10.1021/jf800840u
Shin DS, Compadre CM, Maleki SJ, Kopper RA, Sampson H, Huang SK, et al. Biochemical and structural analysis of the IgE binding sites on Ara h 1, an abundant and highly allergenic peanut protein. J Biol Chem 1998; 273: 13753- 13759. http://dx.doi.org/10.1074/jbc.273.22.13753
Hourihane JB, Bedwani SJ, DeanTaraneh P, Warner JO. Randomised, double blind, crossover challenge study of allergenicity of peanut oils in subjects allergic to peanuts. BMJ 1997; 314: 1084. http://dx.doi.org/10.1136/bmj.314.7087.1084
Burks AW, Williams LW, Helm RM, Connaughton C, Cockrell GOBT. J. Identification of a major peanut allergen, Ara h I, in patients with atopic dermatitis and positive peanut challenges. J Allergy Clin Immunol 1991; 88: 172–179. http://dx.doi.org/10.1016/0091-6749(91)90325-I
