R.I. MONSALVE, M. VILLALBA, R. RODRÍGUEZ
Departamento de Bioquímica y Biología Molecular I, Facultad
de Química, Universidad Complutense de Madrid, Spain
SUMMARY |
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Allergy to mustard seeds has been reported for years,
in many cases as very strong anaphylactic reactions. Recent studies have
shown that this allergy is increasing and that mustard allergens can be
considered among the most important food allergens, especially in countries
where the consumption of mustard seed is high. Clinical studies describing
hypersensitivity to mustard are reviewed in this paper, as well as the
detailed structural and immunological characterization carried out on the
major allergens from yellow (Sinapis alba) and oriental (Brassica
juncea) mustard seeds. These allergens, named Sin a 1 and Bra j 1, respectively,
belong to the 2S albumin class of seed storage proteins.
Homologous 2S albumins from rapeseed (Brassica napus) are also potentially allergenic to mustard-sensitive patients, since they share allergenic determinants with Sin a 1 and Bra j 1. Moreover, in recent years, 2S albumins from several other species have been described as allergens, suggesting that this family of storage proteins is intrinsically allergenic. The availability of three-dimensional data of BnIb, a 2S albumin from rapeseed, has revealed that these proteins are also structurally related to LTPs (lipid transfer proteins) and alpha-amylase/trypsin inhibitors from cereals, which are proteins involved in fruit allergies and baker's asthma disease, respectively. Although their primary structures have significant differences, all these proteins share a common fold of four alpha-helices that are held together by four disulphide bridges. This three-dimensional architecture would therefore have demonstrated itself to be conserved throughout the evolution of such different proteins, and would have given them compactness and stability. These structural features are discussed in terms of their possible relationship with the allergenic character of these groups of plant proteins. |
mustard allergy, 2S albumin, napin-like storage proteins, homology, cysteine pattern, superfamily global fold, structure / allergenicity relationship |
Rafael I. Monsalve |
Correspondence:
Dr. Rafael I. Monsalve Departamento de Bioquímica y Biología Molecular I Facultad de Químicas Universidad Complutense de Madrid 28040 Madrid, Spain Phone: +34-91-3944155 Fax: +34-91-3944159 eMail: rafam@bbm1.ucm.es |
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