on 06-19-201704:07 AM - edited on 10-15-202106:10 AM by Closed Account
Romain Huguet1, Ioanna Ntai1, Andreas FR Huhmer1, and Daniel Lopez-Ferrer1 ASMS 2017 Poster IgE-mediated reactions to fish allergens represent the most frequent cause of food allergy. Fish parvalbumins are very abundant in fish tissue and are the major fish allergen that is contain in the sarcoplasmatic reticulum. These proteins share physicochemical properties that distinguish them from nonallergens, Among those properties, these proteins are usually thermostable, resistant to low pH, to the activity of proteases, etc. All together translates in sufficient gastric stability to reach the intestinal mucosa where absorption and sensitization (development of atopy) can occur. Similar properties are shown in the gas phase when these proteins are ionized their stability makes them very difficult to fragment and to provide proper sequence coverage. Here, we explore their fragmentation patterns and their resistance to be broken down in the gas phase. To this end, a modified Orbitrap Fusion Tribrid mass spectrometer capable of using five different dissociation techniques was used and applied to the characterization of three different fish species that cause allergic reactions of different severities in fish-allergic individuals. Sequence coverage obtained from the MS/MS spectra of the purified proteins showed an agreement with their overall secondary structure contents. In the case, of salmon parvalbumins, one of the most allergenic proteins in fish, very poor fragmentation spectra were obtained when HCD, ETD, EThCD were used. Howeverm UVPD was able to provide a proper MS/MS spectra at 40 milliseconds activation time.