title: Contribution of structural reversibility to the heat stability of the tropomyosin shrimp allergen.
abstract: Tropomyosins are common heat-stable crustacean allergens. However, their heat stability and their effects on antigenicity have not been clarified. We purified tropomyosin in this study from raw kuruma prawns (Marsupenaeus japonicus) without heat processing. SDS-PAGE of the purified protein showed a band at approximately 35 kDa that cross-reacted with IgE from the serum of a shrimp-allergic patient, identifying it as Pen j 1. The circular dichroism spectrum of native Pen j 1 revealed the common α-helical structure of tropomyosins which easily collapsed upon heating to 80 °C. However, there were no insoluble aggregates after heating, and the protein regained its native CD spectral pattern after cooling to 25 °C. There was no significant difference in total IgG production between mice sensitized with native and heated Pen j 1. These results suggest that heat-denatured Pen j 1 refolded upon cooling and maintained its antigenicity following the heat treatment.
authors: Department of Food Science and Technology, National Fisheries University, Nagata-Honmachi, Shimonoseki, Japan. usuim@fish-u.ac.jp
authors: Masakatsu
authors: M
authors: Usui
authors: Akihito
authors: A
authors: Harada
authors: Takayuki
authors: T
authors: Ishimaru
authors: Emiri
authors: E
authors: Sakumichi
authors: Fumihiko
authors: F
authors: Saratani
authors: Chiho
authors: C
authors: Sato-Minami
authors: Hiroyuki
authors: H
authors: Azakami
authors: Taiko
authors: T
authors: Miyasaki
authors: Ken'ichi
authors: K
authors: Hanaoka
mesh_terms: D000485:Allergens / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification; D000818:Animals; D006358:Hot Temperature; D051379:Mice; D033561:Penaeidae / Q000276:immunology*; D055550:Protein Stability; D014335:Tropomyosin / Q000737:chemistry* / Q000276:immunology* / Q000302:isolation & purification
chemical_list: D000485:Allergens; D014335:Tropomyosin