Proteomics-Based Approach To Detect and Identify Major Allergens in Processed Peanuts by Capillary LC-Q-TOF (MS/MS)

• Published in: Journal of agricultural and food chemistry 2007-05, Vol.55 (11), p.4461-4473
• Main Authors: Chassaigne, Hubert, Nørgaard, Jørgen V, van Hengel, Arjon J
• Format: Article
• Language: English
• Subjects: allergens; Allergens - analysis; Amino Acid Sequence; Arachis - chemistry; Arachis hypogaea; Biological and medical sciences; biomarkers; detection; expressed sequence tags; Food industries; food processing; food quality; food safety; Fundamental and applied biological sciences. Psychology; General aspects; heat treatment; high performance liquid chromatography; mass spectrometry; Methods of analysis, processing and quality control, regulation, standards; Molecular Sequence Data; nanoelectrospray quadrupole time-of-flight tandem mass spectrometry; Peanut Hypersensitivity; peanut protein; peanuts; peptides; Plant Proteins - analysis; processed foods; product testing; proteome; proteomics; Proteomics - methods; raw foods; reversed-phase capillary liquid chromatography; roasting; screening; Tandem Mass Spectrometry - methods
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf063630e

An MS-based method, combining reversed-phase capillary liquid chromatography (capillary LC) with quadrupole time-of-flight tandem mass spectrometry (nano-ESI Q-TOF MS/MS), was developed with the aim of identifying a set of peptides that can function as markers for peanut allergens. Emphasis was given to the identification of the three major peanut allergens Ara h 1, Ara h 2, and Ara h 3, because these proteins are considered to represent >30% of the total protein content of peanut and are directly relevant for the allergenic potential of this food. The analytical data obtained were used to perform databank searching in combination with de novo sequencing and led to the identification of a multitude of sequence tags for all three peanut allergens. Food processing such as roasting of peanuts is known to affect the stability of proteins and was shown to influence the detection of allergen sequence tags. The analysis of raw and roasted peanuts allowed the identification of five peanut-specific sequence tags that can function as markers of the specific allergenic proteins. For Ara h 1, two peptide markers were proposed, namely, VLEENAGGEQEER (m/z 786.88, charge 2+) and DLAFPGSGEQVEK (m/z 688.85, charge 2+), whereas for Ara h 2 only one peptide, RQQWELQGDR (m/z 439.23, charge 3+), was found to satisfy the required conditions. For Ara h 3, the two specific peptides, SPDIYNPQAGSLK (m/z 695.35, charge 2+) and SQSENFEYVAFK (m/z 724.84, charge 2+), were selected. Other peptides have been proposed as indicative for food processing. Keywords: Peanut allergens; food processing; tryptic peptides; capillary high-performance liquid chromatography (capillary LC); nanoelectrospray quadrupole time-of-flight tandem mass spectrometry (nano-ESI Q-TOF MS/MS)