Mass spectrometry-based identification of allergens from Curvularia pallescens, a prevalent aerospore in India

• Published in: Biochimica et biophysica acta 2016-07, Vol.1864 (7), p.869-879
• Main Authors: Dey, Debarati, Saha, Bodhisattwa, Sircar, Gaurab, Ghosal, Kavita, Bhattacharya, Swati Gupta
• Format: Article
• Language: English
• Subjects: Allergen; Allergens - analysis; Ascomycota - immunology; Curvularia; Curvularia pallescens; Fungal allergic patients; Humans; Immunoblot; MALDI TOF/TOF; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization - methods; Spores, Fungal
• ISSN: 1570-9639; 0006-3002; 1878-1454
• DOI: 10.1016/j.bbapap.2016.03.012

The worldwide prevalence of fungal allergy in recent years has augmented mining allergens from yet unexplored ones. Curvularia pallescens (CP) being a dominant aerospore in India and a major sensitiser on a wide range of allergic population, pose a serious threat to human health. Therefore, we aimed to identify novel allergens from CP in our present study. A cohort of 22 CP-sensitised patients was selected by positive Skin prick grade. Individual sera exhibited elevated specific IgE level and significant histamine release on a challenge with antigenic extract of CP. First gel-based profiling of CP proteome was done by 1- and 2-dimensional gel. Parallel 1- and 2-dimensional immunoblot were performed applying individual as well as pooled patient sera. Identification of the sero-reactive spots from the 2-dimensional gel was found to be challenging as CP was not previously sequenced. Hence, mass spectrometry-based proteomic workflow consisting of conventional database search was not alone sufficient. Therefore, de novo sequencing preceded homology search was implemented for further identification. Altogether 11 allergenic proteins including Brn-1, vacuolar protease, and fructose-bis-phosphate aldolase were identified with high statistical confidence (p