Determination of Gluten Peptides Associated with Celiac Disease by Mass Spectrometry

Abstract

Gluten is a big protein network composed of monomeric fraction (prolamins) and polymeric fraction (glutelins), occurring in many cereal-based products, especially in those containing wheat. Gluten peptides can trigger food allergies and intolerances, including inflammatory reactions as the celiac disease, an autoimmune disorder of the small intestine characterized by mucosal degeneration and villous atrophy. The treatment is the permanent exclusion of gluten from diet. However, gluten analysis is a very difficult task, due to the high complexity of polypeptides and the lack of consensus on the most appropriate analytical method. Proteomics approaches, combining liquid chromatography and mass spectrometry in tandem (LC-MS/MS), have been pointed as the most promising nonimmunological techniques for gluten detection. LC-MS analyses associated with bioinformatics and specific-prolamin database can solve methodological limitations since it is based on the accurate molecular mass of peptide biomarkers. One of the major contributions of proteomics has been the identification of epitopes of gluten peptides responsible for wheat-related diseases. Recent works have defined grain-specific gluten peptides and also the lowest concentration at which peptides could be confidently detected. Proteomic application for gluten quantification should support not only regulatory limits in processed foods, but also the safety of consumers about food labeled as gluten-free.

Investigation of Protein and Epitope Characteristics of Oats and Its Implications for Celiac Disease

“…The current scientific status about the safety of oats does not provide arguments to categorize certain oat cultivars as really harmful regarding CD. LC-MS (liquid chromatography-mass spectrometry) is the most important tool for the identification and quantification of immunoreactive cereal proteins (49). However, the quantification of gluten epitopes with this precise method can still be limited due to the high cereal protein polymorphism and an incomplete gluten database of oat immune responsive proteins (50).…”

Advances in quantification and analysis of the celiac‐related immunogenic potential of gluten

“…This collision occurs by an inert gas, usually nitrogen or argon, resulting in the formation of product ions, that is, the identified peptides are selected and subjected to fragmentation to elucidate the sequence of amino acids, allowing the confirmation and identification of different sequences (Graves & Haystead, 2002). When associated with LC, the analysis of biomolecules in complex samples is more accurate due to their high levels of sensitivity and specificity (Alves et al., 2017). Still, its wider use is hampered by the high monetary value of the equipment, and not all laboratories are specialized for such analyses (Graves & Haystead, 2002).…”

Gluten Detection in Foods

“…LC-MS/MS can combine with HPLC chromatography with a mass spectrometer where HPLC can digest the peptides on the basis of properties such as size change, hydrophobicity, etc. and also removes the extra salts, buffers from the sample because these molecules can greatly influence the data generated by LC-MS/MS.LC-MS/MS coupled with a mass spectrometer is one of the most important tools used to identify and quantify the immunoreactive cereal proteins (Alves et al, 2017). This coupling chromatographic separation and mass spectrometer detection techniques (LC-MS/MS) allows a large number of sampling in a short duration of time.…”