Physicochemical properties and thermal stability of Lep w 1, the major allergen of whiff.
Whiff (Lepidorhombus whiffiagonis) is a fish frequently consumed in Spain. Lep w 1, its major allergen, is a calcium-binding beta-parvalbumin. The resistance of Lep w 1 to heat denaturation and to digestion were studied by circular dichroism spectroscopy and by in vitro gastric digestion systems. Purified Lep w 1 was thermally stable up to 65 degrees C at neutral pH. Calcium depletion resulted in a change of its structure as determined by circular dichroism spectroscopy. A partial loss of structure was also observed at acidic pH; however, the allergen retained its full IgE-binding ability. The partially denatured Lep w 1 was easily digested by pepsin within 2 min. Further, the IgE reactivity of proteins extracted from cooked fish and their stability to proteolysis were analyzed. The extract revealed a higher number of IgE reactive bands than an extract from uncooked fish. IgE binding to these proteins could not be inhibited by an extract from uncooked fish. In contrast to a raw fish extract, the cooked extract showed higher resistance to pepsinolysis. The stability of Lep w 1 to thermal denaturation and digestion explains the high allergenicity of whiff.
Griesmeier
Ulrike
U
Department of Pathophysiology, Medical University of Vienna, Waehringer Guertel 18-20, Vienna, Austria.
Bublin
Merima
M
Radauer
Christian
C
Vázquez-Cortés
Sonia
S
Ma
Yan
Y
Fernández-Rivas
Montserrat
M
Breiteneder
Heimo
H
D000485:Allergens / Q000737:chemistry* / Q000302:isolation & purification; D000818:Animals; D002942:Circular Dichroism; D005399:Fishes / Q000276:immunology*; D005512:Food Hypersensitivity / Q000209:etiology*; D006358:Hot Temperature; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood; D008958:Models, Molecular; D010320:Parvalbumins / Q000276:immunology / Q000378:metabolism
D000485:Allergens; D010320:Parvalbumins; D007073:Immunoglobulin E