Characterization of Pollen Specific Proteins SF3 and SF21 from Sunflower ( Helianthus annuus L . ) for the Allergenicity Potential

Abstract

Pollen from different type of plants carry different proteins that are more likely to become allergenic than others. In this study pollen specific proteins SF3 and SF21 from Sunflower (Helianthus annuus) were in-silico characterized for allergenicity potential. Bioinformatics allergen prediction tools were employed for prediction of SF3 and SF21 as candidate allergens. The phylogenetic relationship between the pollen specific proteins and protein allergens of Asteraceae family was also analyzed to unveil their similarity. The results by Bepipred Linear Epitope prediction demonstrated a good number of epitopes in pollen specific protein SF3 and SF21 signifying that both are potential allergens. However, further analysis through ConSurf revealed the presence of allergen-specific patches with remarkably higher proportion of surface-exposed hydrophobic residue in SF3 than SF21. Further prediction by AlgPred and ProAp methods with Support Vector Machines (SVMs) revealed that only SF3 contained IgE epitope thus confirming it as a potential allergen. The phylogenetic analysis revealed a close identity of SF3 with the major allergen of Ambrosia artemisiifolia pollen, Amb a 3. The study has demonstrated high allergenic activity of SF3 protein with shared similarity with the pollen protein allergens of Asteraceae family. This study forms a basis in predicting cross-reactivity of pollen specific proteins, designing of therapeutic procedures and evaluating the allergenic potential of novel proteins.