The chromatograms show the three MRM transitions of peptide GGLEPINFQTAADQAR (+2y10black; +2y12 + 2red; +3y5blue)

The chromatograms show the three MRM transitions of peptide GGLEPINFQTAADQAR (+2y10black; +2y12 + 2red; +3y5blue). The results from conventional SPE LC-MS/MS experiments without immunoaffinity clean-up using different volumes are shown inFigure 7. an important option strategy for the detection and quantification of allergens in food. Keywords:egg allergen, monoclonal antibodies, allergen detection, processed food, mass spectrometry, Gal d 2 == 1. Introduction == Food allergy is usually a potentially life-threatening immunological disorder caused Rabbit Polyclonal to VEGFB by hypersensitivity to specific food allergens. There is currently no cure, so strict avoidance is required to prevent allergic reactions. Allergen analysis can identify and/or verify the presence of allergenic ingredients and unwanted (cross-contact) allergens in food throughout the production process from farm to fork, and is used by food suppliers, food producers, retailers and food safety agencies to ensure the availability of safe products for those with food allergies. Multiple analytical methods are available for the direct detection of allergenic food proteins, including the enzyme linked immunosorbent assay (ELISA), lateral flow devices (LFDs), and liquid chromatography tandem mass spectrometry (LC-MS/MS) [1,2]. Alternatively, the presence of allergens can be inferred indirectly by identifying the corresponding DNA sequence by real-time PCR [3]. Commercial ELISA and PCR kits are available for most important food allergens defined by current legislation. However, allergens from egg-white cannot be detected by PCR because egg white contains Pyrotinib Racemate very little to no DNA [4]. Despite continuous improvements in detection methods, there is no universally superior technique and each of the methods listed above has unique advantages and disadvantages, creating issues with comparability across different assay formats [5,6]. A great advantage of antibody-based methods, regardless of which antibody is selected, is that detergents can be used during extraction, even with harsh procedures using 12% SDS with subsequent dilution to at least 0.05%. In contrast, most detergents interfere with LC-MS/MS analysis and extraction is therefore less efficient, hence the sensitivity of such methods remains unsatisfactory [7]. To combine the advantages of antibody-based and MS-based methods, we developed a proof-of-concept immunoaffinity LC-MS/MS technique using the common egg allergen Gal d 2 [8] as a case study. The Pyrotinib Racemate selection of monoclonal antibodies for allergen detection is usually based on immunization with total protein extracts followed by screening without knowledge of the epitope sequence. In contrast, we screened for antibodies using peptides already known to be applicable in MS analysis. The resulting antibodies can be used for the affinity purification of allergens to improve the sensitivity of MS quantification [9]. We also investigated the treatment of egg proteins with heat (baking) and high hydrostatic pressure as examples of rigorous processing steps that influence both antigenantibody interactions Pyrotinib Racemate and peptide mapping [10,11]. Such processes cause the fundamental reorganization of protein structure by interfering with physical and chemical interactions such as Van der Waals forces and hydrogen bonds [12]. However, the covalent bonds that maintain the primary structure of linear epitopes and govern their interactions with peptide-specific antibodies should be preserved, facilitating detection by immunoaffinity clean-up and MS as discussed herein. Finally, we compared the performance Pyrotinib Racemate of our new immunoaffinity method to a traditional ELISA for the detection of the egg allergen Gal d 2. == 2. Materials and Methods == == 2.1. Selection of Suitable Tryptic Peptides for Gal d 2 == Peptide selection was based on the 33 predicted trypsin cleavage sites in Gal d 2 matching the consensus (RK).[^P]. At least 12 of the resulting 34 peptides (Table 1) have been used by other authors to detect Gal d 2 by mass spectrometry based analytical approaches [13,14,15,16,17]. We.