Elena Barletta   Elena Barletta holds a bachelor degree in biology from the University of Rome “Tor Vergata” (Italy) and a master degree in biology from the University of Geneva (Switzerland). During her master degree study at the University of Geneva and the Swiss Institute of Bioinformatics (SIB), her project was focused on the analysis and interpretation of proteomics data, mainly of mass-spectrometry. She worked on post-translational modifications and on the identification of diagnostic and prognostic markers for different types of cancer, focusing on glycosylation and glyco-epitopes differentiation. After receiving her master's degree, she started working as a research intern in the Faculty of Medicine (University of Geneva) and was involved in a research project on the biochemical analysis of blood and saliva proteins, characterization and quantification, through mass-spectrometry techniques, for the diagnosis and classification of amyloidosis pathologies, potentially revealing new biomarkers for early detection and targeted therapeutic treatments. She is currently a Ph.D. student (University of Zurich) at the Swiss Institute of Allergy and Asthma Research (SIAF) and her project is focused on the identification of proteoforms involved in allergic diseases using mass spectrometry technologies.

Mass Spectrometry-based Identification of Allergen Proteins Involved in Seafood-related Allergic Reactions

Shellfish are one of the most common causes of food allergies and a major cause of food-induced anaphylaxis. The prevalence of seafood allergy is higher in populations residing in coastal geographic areas where seafood is an integral part of their diet. Sensitization and subsequent reactions occur most frequently upon ingestion. However, they can also occur because of skin contact. Shrimps are, among all, the most consumed type of seafood worldwide and for that, it is important to identify and characterize all possible allergens. A bottom-up proteomics approach, LC-MS/MS coupled with Parallel Reaction Monitoring (PRM) technique, is used to acquire high-resolution full MS/MS spectra for each target allergen peptide. Total protein extracts from shrimp (Penaeus monodon and Penaeus vannamei) were isolated and processed through in-gel tryptic digestion of SDS-PAGE gel fractions.The resulting peptides were then collected and purified prior to LC-MS/MS analysis and the MS raw files were processed by the SEQUEST algorithm within the protein database for decapods (TaxID = 6683). In all shrimp samples, it was possible to accurately identify our proteins of interest. Tropomyosin proteins specific for shrimp, prawns, lobster, and crab were identified in our discovery workflow sharing a sequence identity between 89% and 100%. To support our findings, a PRM analysis was then performed looking for all shrimp unique tropomyosin peptides. A transition list for each peptide, from in silico digestion, is generated and analyzed within the Skyline open-source software. It was possible to confirm the presence of the tropomyosin allergen and the results obtained suggest the reproducibility of this proteomics workflow, so as to be used not only in the identification of other important allergens in seafood-related allergic reactions but also of allergens involved in other types of allergic diseases.