title: Absolute quantification of protein NP24 in tomato fruit by liquid chromatography/tandem mass spectrometry using stable isotope-labelled tryptic peptide standard.
abstract: Protein NP24 is a thaumatin-like protein contained in tomato (Lycopersicon esculentum Mill.). This protein is reported to be a putative tomato allergen and is listed as a food allergen in Structural Database of Allergenic Proteins (SDAP). In this research, we developed the quantitative analysis of NP24 by employing the protein absolute quantification (AQUA) technology composed of stable isotope-labelled internal standard (SIIS) peptide (GQTWVINAPR[(13)C6,(15)N4]) and liquid chromatography/tandem mass spectrometry (LC/MS/MS). A linear relationship (r(2)>0.99) was found throughout the concentration range (2.0-500 fmol/μL). The coefficients of variation (CVs) measured on each of the five days when NP24 contained in the tomato skin was analysed did not exceed 13%. Our developed assay of NP24 will contribute to the allergological examination of tomato and its derived products.
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan. Electronic address: ippoushi@affrc.go.jp.
authors.forename: Katsunari
authors.initials: K
authors.lastname: Ippoushi
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Motoe
authors.initials: M
authors.lastname: Sasanuma
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Hideaki
authors.initials: H
authors.lastname: Oike
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Masuko
authors.initials: M
authors.lastname: Kobori
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Mari
authors.initials: M
authors.lastname: Maeda-Yamamoto
mesh_terms: D000485:Allergens / Q000737:chemistry; D000595:Amino Acid Sequence; D002853:Chromatography, Liquid; D005638:Fruit / Q000737:chemistry*; D007553:Isotope Labeling; D018551:Solanum lycopersicum / Q000737:chemistry*; D008969:Molecular Sequence Data; D010940:Plant Proteins / Q000737:chemistry*; D053719:Tandem Mass Spectrometry
chemical_list: D000485:Allergens; D010940:Plant Proteins; C003427:thaumatin protein, plant
keywords: Absolute quantification; Liquid chromatography/tandem mass spectrometry; Lycopersicon esculentum Mill.; Protein NP24; Stable isotope-labelled peptide; Tomato; Trypsin