title: High-throughput NMR assessment of the tertiary structure of food allergens.
abstract: BACKGROUND
  In vitro component-resolved diagnosis of food allergy requires purified allergens that have to meet high standards of quality. These include the authentication of their conformation, which is relevant for the recognition by specific IgE antibodies from allergic patients. Therefore, highly sensitive and reliable screening methods for the analysis of proteins/allergens are required to assess their structural integrity. In the present study one-dimensional 1H Nuclear Magnetic Resonance (1D 1H-NMR) analysis was adopted for the assessment of overall structural and dynamic properties and authentication of a set of relevant food allergens, including non-specific lipid transfer proteins from apple, peach and hazelnut, 7/8S seed storage globulins from hazelnut and peanut, 11S seed storage globulins from hazelnut and peanut, caseins from cows' and goats' milk and tropomyosin from shrimp.
  
  
  RESULTS
  Two sets of 1D 1H-NMR experiments, using 700 MHz and 600 MHz instruments at 298 K were carried out to determine the presence and the extent of tertiary structure. Structural similarity among members of the individual allergen families was also assessed and changes under thermal stress investigated. The nuclear magnetic resonance (NMR) results were compared with structural information available either from the literature, Protein Data Bank entries, or derived from molecular models.
  
  
  CONCLUSIONS
  1D (1)H-NMR analysis of food allergens allowed their classification into molecules with rigid, extended and ordered tertiary structures, molecules without a rigid tertiary structure and molecules which displayed both features. Differences in thermal stability were also detected. In summary, 1D (1)H-NMR gives insights into molecular fold of proteins and offers an independent method for assessing structural properties of proteins.
authors: CERM, Centro di Ricerca di Risonanze Magnetiche and Department of Agricultural Biotechnology, University of Florence, Florence, Italy.
authors: Stefano
authors: S
authors: Alessandri
authors: Ana
authors: A
authors: Sancho
authors: Stefan
authors: S
authors: Vieths
authors: Clare E N
authors: CE
authors: Mills
authors: Jean-Michel
authors: JM
authors: Wal
authors: Peter R
authors: PR
authors: Shewry
authors: Neil
authors: N
authors: Rigby
authors: Karin
authors: K
authors: Hoffmann-Sommergruber
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000145:classification / Q000276:immunology; D052179:Antigens, Plant / Q000737:chemistry* / Q000145:classification / Q000276:immunology; D002352:Carrier Proteins / Q000737:chemistry* / Q000145:classification / Q000276:immunology; D031211:Corylus / Q000737:chemistry* / Q000276:immunology; D005504:Food Analysis / Q000379:methods; D005512:Food Hypersensitivity / Q000276:immunology; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D027845:Malus / Q000737:chemistry* / Q000276:immunology; D010940:Plant Proteins / Q000737:chemistry* / Q000145:classification / Q000276:immunology; D017434:Protein Structure, Tertiary; D027861:Prunus / Q000737:chemistry* / Q000276:immunology
chemical_list: D000485:Allergens; D052179:Antigens, Plant; D002352:Carrier Proteins; D010940:Plant Proteins; C030363:lipid transfer protein