Avaliação in silico da alergenicidade de proteínas Cry expressas em cultivares transgênicas liberadas para comercialização no Brasil: uso de novas abordagens e ferramentas

Abstract

Currently, much of the world's food production comes from Genetically Modified Organisms (GMOs). Crops of GMOs, also called events, have now approval to cultivation and trade in 75 countries, covering more than 180 million hectares of land and it is increasing each day. However, there are factors to consider about these products. Proteins introduced into crops by genetic modification can generate compounds different from their conventional counterparts and suffer unintended effects, which may result in the formation of an allergen. The Food and Agriculture Organization of the United Nations and the World Health Organization (FAO / WHO) establish concepts and approaches for safety assessments of genetically modified crops, but these tests have limitations that require studies using new information, tools and approaches to be overcome. This work sought to use in silico analyses to carry out a risk reassessment regarding the allergenicity of 13 Cry proteins expressed in transgenic cultivars released for commercialization in Brazil, since 2005, considering the need for updating that is inherent to such evaluations. A review of the literature on the allergenicity of Cry proteins was made followed by a search in databases for Cry protein sequence similarity with known allergens. Also, the similarity of each protein with known allergens was investigated by means of remote homology prediction, prediction of homology based on linear motifs and identity of physicochemical properties. Finally, the stability of Cry proteins against in silico sequential digestion was analysed. It was found that the Cry proteins approved for commercialization in Brazil maintained a in silico safety profile in relation to Food Allergy after a reevaluation with new tools and approaches.