Decloedt, Anneleen

Van Landschoot, Anita

Vanderputten, Dana

Watson, Hellen

English

Ghent University Academic Bibliography

DETECTION AND QUANTIFICATION OF BARLEY GLUTEN PEPTIDES  BY STATE-OF-THE-ART MASS SPECTROMETRY H. Watson1, A. Decloedt1,2,3, D. Vanderputten2, A. Van Landschoot1,2 A total of 115 different hordein-derived and Avenin-like A protein-derived peptides  were  previously characterized in commercial malt beers [1-6]. 1 Ghent University, Faculty of Bioscience Engineering, Laboratory of Biochemistry and Brewing, Ghent, Belgium; 2 University College Ghent, Faculty of Nature and Technology,  Laboratory of Biochemistry and Brewing, Ghent, Belgium; 3 Ghent University, Faculty of Veterinary Medicine, Laboratory of Chemical Analysis, Merelbeke, Belgium Hordein T-cell epitope Reference Hordein T-cell epitope Reference QQPFPQQPQ QQPQQPFPL C QPQQPFPL QPQQPFPQQ [3] C QQPQQPFPL QPHQP [4] C QIPTPL QPQQPFPQQ [3] AELIIP QQPQQPFPL QPHQP [2] QIPTPLQP QQPFPQQPQ QPL [3] IIP QQPQQPFPL QPHQP [2] QQPQQPFPQ AELIIP QQPQQPFPL [3] C QPFP QQPQQPFPQ PQ [3] ELIIP QQPQQPFPL QPHQPYTQQT [3] C TPLQPQ QPFPQQPQQ PL [3] ELIIP QQPQQPFPL QPHQPY [3] C IIPQQPFPLQP QPFPQQPQQ PLPQPQQP [2] ELIIP QQPQQPFPL QPHQPYTQ [3] QQPQQPYPQ ELIIP QQPQQPFPL Q [3] B1 QP QPYPQQPQQ PFPPQ [5] C QIIP QQPQQPFPL QPHQPY [3] PYPQQPQQP B3 IIP QQPQQPFPL QPQQPQPFPQQPI [6] B1 QPQ PYPQQPQQP FPPQ [5] IIP QQPQQPFPL QPQ [3] Table: Peptides with a complete T-cell epitope characterized in beers DETECTION AND QUANTIFICATION OF HORDEIN PEPTIDES IN BELGIAN MALT BEERS BY HR-ORBITRAP-MS To comply with ‘gluten-free’ (< 20 ppm) labeling legislation, sensitive and reliable methods for gluten quantification in food and beverages are required.   Standard approach: LC-MS-based methods in MRM-mode   Relies upon chemical and physical properties of gluten peptides originating from a trypsin digest  High degree of specificity A characterization study of gluten peptides in beer after an in vitro tryptic digest showed that the majority of the peptides (> 50%) are semitryptic [2]  New approach: UHPLC-HR-Orbitrap-MS  Allows full-scan MS experiments with post-acquistion ion selection More hordein-derived peptides can be analysed  High mass resolution and accurate mass measurements offers the ability for highly sensitive, accurate and unambiguous detection and quantification of hordein-derived peptides REFERENCES: [1] Picariello et al., Food Chem., 2011 124:1718-1726; [2] Colgrave et al., J. Proteome Res., 2012 11:386-396; [3] Comino et al., J. Sci. Food Agric., 2012 93:933-943;  [4] Picariello et al., J. Proteomics, 2012 75:5872-25582; [5] Colgrave et al., J. Chromatogr. A., 2014 1370:105-114; [6] Real et al., PLoS ONE, 2014 9(6):e100917 monomeric polymeric C-hordeins γ-hordeins B-hordeins D-hordeins Avenin-like A 10-20% 1-2% 70-80% 2-4% 18 ≠ peptides 26 ≠ peptides 38 ≠ peptides 30 ≠ peptides 75% Gluten 3 ≠ peptides Gluten are one of the 14 official listed allergens by the European Food Safety Authority. Consumption of gluten can cause health implications in individuals with a gluten intolerance or allergy. Awareness of allergens in food and beverages is an upcoming trend in the food industry as well as by regulation authorities. Directive 41/2009/EC defines ‘gluten-free’ (< 20 ppm) food and beverages.  BARLEY HORDEINS AND PEPTIDES IN BEER  Gluten are storage proteins found in the starchy endosperm of barley, wheat and rye kernels. In barley, gluten proteins are named hordeins and account for 75% of the total protein content. Hordeins are a complex polymorphic mixture composed of B-, C-, D- and γ-hordein families. Avenin-like type A storage proteins are foam promoting components that share sequence homology with γ-hordeins.  Malt derived from germinated barley is the basic ingredient in traditional brewing. Through the sequential processes of malting, mashing and brewing hordeins are hydrolysed partially to peptides or completely to amino acids.  IMMUNOGENIC AND TOXIC PROPERTIES OF HORDEIN PEPTIDES IN BEER  Characteristic to all hordeins and derived peptides are the high levels of the amino acid proline making them difficult to degrade by gastrointestinal enzymes. As a result, relatively large hordein-derived peptides enter the small intestine where they can elicit an immune response leading to inflammatory damage in genetically predisposed individuals. So far, 29 immunogenic epitopes causing a T-cell mediated immune response have been described. 39 out of the 115 characterized peptides share a minimal of six residues to one or more of the known T-cell epitopes, rendering them likely to possess immunogenicity. Known T-cell epitopes within hordein-derived peptides are shown in bold. Known T-cell epitopes  present in opposite direction are shown in italics. 

Detection and quantification of barley gluten peptides by state-of-the-art mass spectrometry

https://biblio.ugent.be/publication/7105412/file/8024867.pdf

Detection and quantification of barley gluten peptides by state-of-the-art mass spectrometry

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