Using Proteomic Strategies for Sequencing and Post-Translational Modifications Assignment of Antigen-5, a Major Allergen from the Venom of the Social Wasp Polybia paulista

• Published in: Journal of proteome research Vol. 13; no. 2; pp. 855 - 865
• Main Authors: dos Santos-Pinto, José Roberto Aparecido, dos Santos, Lucilene Delazari, Andrade Arcuri, Helen, Castro, Fábio Morato, Kalil, Jorge Elias, Palma, Mario Sergio
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 07.02.2014
• Subjects: Allergens - chemistry; Allergens - immunology; Amino Acid Sequence; Animals; Electrophoresis, Gel, Two-Dimensional; Molecular Sequence Data; Protein Processing, Post-Translational; Proteomics; Sequence Homology, Amino Acid; Wasp Venoms - immunology; Wasps; allergen; mass spectrometry; peptide sequence; post-translational modification; molecular modeling
• ISSN: 1535-3893; 1535-3907
• DOI: 10.1021/pr4008927

Antigen-5 is one of the major allergens identified in wasp venoms, and despite the fact that its biological function is still unknown, many studies have demonstrated its allergenicity. In this study, the biochemical and structural characterization of antigen-5 from the venom of the social wasp Polybia paulista are reported. A gel-based mass spectrometry strategy with CID fragmentation methods and classical protocols of protein chemistry, which included N- and C-terminal sequencing, were used to assign the complete sequence and determine the presence/location of the post-translational modifications (PTMs) of this protein. Six different isoforms of antigen-5 were identified in the crude venom of P. paulista; the most abundant, which corresponds to the intact form of this protein, was recognized by the pool of human specific-IgE. This protein was extensively sequenced through CID mass spectrometry, and a series of PTMs were observed such as hydroxylation, phosphorylation, and glycosylation. Sequence data revealed that this protein has 59.3–93.7% identity with antigen-5 proteins from other known vespid venoms. The molecular model of P. paulista antigen-5 shows that this protein has three α-helices, one 310 helix, and four β-sheets covering 28 and 17.9% of the sequence, respectively. The identification and characterization of allergenic compounds is essential for the development of advanced component-resolved allergy diagnostics and treatment.