title: Characterization of potential allergens in fenugreek (Trigonella foenum-graecum) using patient sera and MS-based proteomic analysis.
abstract: BACKGROUND
  Fenugreek is a legume plant used as an ingredient of curry spice. Incidents of IgE-mediated food allergy to fenugreek have been reported. Coincidence with allergy to peanut, a major food allergen, seems to be common suggesting a rather high rate of cross-reactivity.
  
  
  OBJECTIVE
  Characterization of fenugreek allergens using patient sera and mass spectrometry-based proteomic analysis.
  
  
  METHODS
  Allergenic fenugreek proteins were detected by immunoblotting, using sera from 13 patients with specific IgE to peanut and fenugreek. IgE-binding proteins were analyzed by peptide mass fingerprinting and peptide sequencing.
  
  
  RESULTS
  A fenugreek protein quintet in the range from 50 kDa to 66 kDa showed high IgE-affinity, the protein at 50 kDa reaching the strongest signals in all patients. Proteomic analyses allowed the classification of several fenugreek proteins to a number of allergen families. Fenugreek 7S-vicilin and 11S-legumin were partly sequenced and revealed considerable homologies to peanut Ara h 1 and Ara h 3, respectively. The presence of a fenugreek 2S albumin and pathogenesis-related (PR-10) plant pollen protein was assumed by database searching results.
  
  
  CONCLUSIONS
  In this study, individual fenugreek proteins were characterised for the first time. Observed homologies to major peanut allergens provide a molecular explanation for clinical cross-reactivity.
authors.affiliation: National Veterinary Institute, Oslo, Norway. christiane.faste@vetinst.no
authors.forename: Christiane Kruse
authors.initials: CK
authors.lastname: Faeste
authors.forename: Uwe
authors.initials: U
authors.lastname: Christians
authors.forename: Eliann
authors.initials: E
authors.lastname: Egaas
authors.forename: Karen R
authors.initials: KR
authors.lastname: Jonscher
mesh_terms: D052179:Antigens, Plant / Q000097:blood / Q000737:chemistry* / Q000276:immunology*; D005240:Feasibility Studies; D005512:Food Hypersensitivity / Q000097:blood / Q000276:immunology; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D010449:Peptide Mapping / Q000379:methods*; D012698:Serologic Tests / Q000379:methods; D029910:Trigonella / Q000276:immunology*
chemical_list: D052179:Antigens, Plant