title: Proteomics and immunological analysis of a novel shrimp allergen, Pen m 2.
abstract: Shellfish are a common cause of adverse food reactions in hypersensitive individuals and shrimp is one of the most frequently reported causes of allergic reactions. A novel allergen from Penaeus monodon, designated Pen m 2, was identified by two-dimensional immunoblotting using sera from subjects with shrimp allergy, followed by matrix-assisted laser desorption ionization time-of-flight mass spectrometry analysis of the peptide digest. This novel allergen was then cloned and the amino acid sequence deduced from the cDNA sequence. The cloned cDNA encoded a 356-aa protein with an acetylated N terminus at Ala2, identified by postsource decay analysis. Comparison of the Pen m 2 sequence with known protein sequences revealed extensive similarity with arginine kinase (EC 2.7.3.3) from crustaceans. Pen m 2 was purified by anion exchange chromatography and shown to have arginine kinase activity and to react with serum IgE from shrimp allergic patients and induce immediate type skin reactions in sensitized patients. Using Pen m 2-specific antisera and polyclonal sera from shrimp-sensitive subjects in a competitive ELISA inhibition assay, Pen m 2 was identified as a novel cross-reactive Crustacea allergen. This novel allergen could be useful in allergy diagnosis and in the treatment of Crustacea-derived allergic disorders.
authors.affiliation: Institute of Biochemistry and Molecular Biology, College of Medicine, National Taiwan University, Taipei, Taiwan.
authors.forename: Chia-Jung
authors.initials: CJ
authors.lastname: Yu
authors.forename: Yu-Fen
authors.initials: YF
authors.lastname: Lin
authors.forename: Bor-Luen
authors.initials: BL
authors.lastname: Chiang
authors.forename: Lu-Ping
authors.initials: LP
authors.lastname: Chow
mesh_terms: D000485:Allergens / Q000032:analysis* / Q000097:blood / Q000276:immunology* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000818:Animals; D001122:Arginine Kinase / Q000032:analysis / Q000276:immunology; D060829:Arthropod Proteins; D003001:Cloning, Molecular; D003429:Cross Reactions; D003445:Crustacea / Q000201:enzymology / Q000276:immunology; D015180:Electrophoresis, Gel, Two-Dimensional; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000096:biosynthesis / Q000097:blood; D008969:Molecular Sequence Data; D033561:Penaeidae / Q000201:enzymology / Q000276:immunology*; D010446:Peptide Fragments / Q000032:analysis / Q000276:immunology; D040901:Proteomics / Q000379:methods; D011817:Rabbits; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D000485:Allergens; D060829:Arthropod Proteins; C471353:Pen m 2 allergen, shrimp; D010446:Peptide Fragments; D007073:Immunoglobulin E; D001122:Arginine Kinase