title: Identification of the major allergen of Macrobrachium rosenbergii (giant freshwater prawn).
abstract: OBJECTIVE
  To characterize the major allergens of Macrobrachium rosenbergii (giant freshwater prawn).
  
  
  METHODS
  Raw and cooked extracts of the giant freshwater prawn were prepared. The IgE reactivity pattern was identified by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting technique with the sera of 20 skin prick test (SPT) positive patients. The major allergen identified was then characterized using the proteomics approach involving a combination of two-dimensional (2-DE) electrophoresis, mass spectrometry and bioinformatics tools.
  
  
  RESULTS
  SDS-PAGE of the raw extract showed 23 protein bands (15-250 kDa) but those ranging from 40 to 100 kDa were not found in the cooked extract. From immunoblotting experiments, raw and cooked extracts demonstrated 11 and 5 IgE-binding proteins, respectively, with a molecular mass ranging from 15 to 155 kDa. A heat-resistant 36 kDa protein was identified as the major allergen of both extracts. In addition, a 42 kDa heat-sensitive protein was shown to be a major allergen of the raw extract. The 2-DE gel fractionated the prawn proteins to more than 50 different protein spots. Of these, 10 spots showed specific IgE reactivity with patients' sera. Matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) analysis led to identification of 2 important allergens, tropomyosin and arginine kinase.
  
  
  CONCLUSIONS
  It can be concluded that the availability of such allergens would help in component-based diagnosis and therapy of prawn allergies.
authors.affiliation: Allergy and Immunology Research Centre, Institute for Medical Research, Jalan Pahang, 50588 Kuala Lumpur, Malaysia.
authors.forename: Zailatul Hani Mohamad
authors.initials: ZH
authors.lastname: Yadzir
authors.forename: Rosmilah
authors.initials: R
authors.lastname: Misnan
authors.forename: Noormalin
authors.initials: N
authors.lastname: Abdullah
authors.forename: Faizal
authors.initials: F
authors.lastname: Bakhtiar
authors.forename: Masita
authors.initials: M
authors.lastname: Arip
authors.forename: Shahnaz
authors.initials: S
authors.lastname: Murad
mesh_terms: D000485:Allergens / Q000302:isolation & purification*; D000818:Animals; D019295:Computational Biology; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D005618:Fresh Water; D006801:Humans; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000276:immunology; D013058:Mass Spectrometry; D008970:Molecular Weight; D033541:Palaemonidae / Q000737:chemistry*
chemical_list: D000485:Allergens; D007073:Immunoglobulin E
keywords: 2-DE electrophoresis; Arginine kinase; IgE reactivity; Immunoblotting; MALDI-TOF; Macrobrachium rosenbergii; Major allergen; SDS-PAGE; Tropomyosin