title: Isolation and identification of an 11S globulin as a new major allergen in mustard seeds.
abstract: BACKGROUND
  Although mustard seed allergy has been largely reported during the preceding 20 years, currently only 2 allergens, Sin a 1 and Bra j 1, have been identified.
  
  
  OBJECTIVE
  To improve the characterization of the allergenic profile of yellow mustard seeds by reporting the identification and biochemical characterization of an 11S globulin as a new major allergen.
  
  
  METHODS
  Mustard seed proteins were separated using size exclusion and ion-exchange chromatographic columns, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and 2-dimensional polyacrylamide gel electrophoresis. Separation of different polypeptide chains was achieved by reverse-phase high-performance liquid chromatography. Mass spectrometry after tryptic digestion and Edman degradation were used to determine amino acid sequences of peptides. IgE binding assays were performed with 13 serum samples from mustard allergic patients in immunoblotting and enzyme-linked immunosorbent inhibition assays.
  
  
  RESULTS
  A protein of 51 kDa was recognized as a major allergen by patients allergic to mustard and called Sin a 2. The allergen was dissociated in 2 chains of 36 and 23 kDa, which also bound IgE. N-terminal end and internal amino acid sequences allowed identification of the new allergen as a seed storage 11S globulin belonging to the Cupin super family. Purified allergen was able to inhibit the IgE binding of sera from allergic patients to mustard seeds extract in up to 55% of the responses.
  
  
  CONCLUSIONS
  An 11S globulin storage protein has been isolated and identified as a novel major allergen of mustard seeds.
authors.affiliation: Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas, Universidad Complutense, Madrid, Spain.
authors.forename: Oscar
authors.initials: O
authors.lastname: Palomares
authors.forename: Javier
authors.initials: J
authors.lastname: Cuesta-Herranz
authors.forename: Andrea
authors.initials: A
authors.lastname: Vereda
authors.forename: Sofía
authors.initials: S
authors.lastname: Sirvent
authors.forename: Mayte
authors.initials: M
authors.lastname: Villalba
authors.forename: Rosalía
authors.initials: R
authors.lastname: Rodríguez
mesh_terms: D000293:Adolescent; D000328:Adult; D000485:Allergens / Q000009:adverse effects / Q000276:immunology / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000937:Antigen-Antibody Reactions; D052179:Antigens, Plant; D001249:Asthma / Q000097:blood / Q000209:etiology; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007106:Immune Sera / Q000276:immunology; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009149:Mustard Plant / Q000009:adverse effects; D010940:Plant Proteins / Q000009:adverse effects / Q000276:immunology / Q000302:isolation & purification*; D012220:Rhinitis / Q000097:blood / Q000209:etiology; D055314:Seed Storage Proteins; D012639:Seeds / Q000009:adverse effects
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D007106:Immune Sera; D010940:Plant Proteins; D055314:Seed Storage Proteins; C512826:Sin a 2 protein, Sinapis alba; C079479:Sin a I protein, Sinapis alba; C059777:cruciferin protein, Brassica napus; D007073:Immunoglobulin E