Identification and characterization of a new IgE-binding protein in mackerel (Scomber japonicus) by MALDI-TOF-MS

Abstract

As fish is one source of the 'big eight' food allergens, the prevalence of fish allergy has increased over the past few years. In order to better understand fish allergy, it is necessary to identify fish allergens. Based on the sera from fish-allergenic patients, a 28 kDa protein from local mackerel (Scomber japonicus), which has not been reported as a fish allergen, was found to be reactive with most of the patients' sera. The 28 kDa protein was analyzed by MALDI-TOF-MS (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry). Mascot search in NCBI database (Date: 08/07/2010) showed that the top protein matched, i.e. triosephosphate isomerase (TPI) from Xiphophorus maculatus and Poecilia reticulata, had a mowse (molecular weight search) score of 98. In addition, TPI from Epinephelus coioides also matched this mackerel protein with a mowse score of 96. Because TPI is considered as an allergen in other non-fish organisms, such as lychee, wheat, latex, archaeopotamobius (Archaeopotamobius sibiriensis) and crangon (Crangon crangon), we consider that it may also be an allergen in mackerel.

The matrix interference to the immunoassay of food samples: The effect of some proteins in aquatic products

“…The protein content in crude fish protein extracts or isolated protein fractions by sephadex G-100 was adjusted to a final concentration of 1 mg mL −1 with water. The discontinuous SDS-PAGE was performed according to the procedure described by Wang, Li, Zheng, Liu, and Lin (2011) under the denatured condition. The stacking and separating gels contained 50 and 150 g L −1 of acrylamide (Sigma, St Louis, MO, USA), respectively.…”

Tropomyosin and Actin Identified as Major Allergens of the Carpet Clam (Paphia textile) and the Effect of Cooking on Their Allergenicity

“…Allergens are often characterized by having the following traits: the ability to sensitize a genetically predisposed individual by triggering the production of IgE antibodies, the ability to bind those particular IgE antibodies, and the ability to cause an allergic reaction following IgE-binding [ 25 , 26 ]. Major allergens are defined on the basis of the frequency of recognition by serum IgE antibodies; that is, a frequency of greater than 50% justifies a designation as a major allergen [ 27 ]. In this study, a protein with molecular mass of 37 kDa was detected in 81% of the sera tested; thus, this 37 kDa protein was identified as one of the major allergens of this clam.…”

The effect of fish matrix on the enzyme‐linked immunosorbent assay of antibiotics

“…The protein in fish extracts or isolated protein fractions was adjusted to a final concentration of 1 mg mL −1 with water. Discontinuous SDS‐PAGE was performed according to the procedure of Wang et al . under denatured conditions.…”

“…The protein in fish extracts or isolated protein fractions was adjusted to a final concentration of 1 mg mL −1 with water. Discontinuous SDS-PAGE was performed according to the procedure of Wang et al 17 under denatured conditions. The stacking and separating gels contained 50 and 150 g L −1 acrylamide (Sigma, St Louis, MO, USA) respectively.…”