Identification of tropomyosin as a major allergen in the octopus Octopus vulgaris and elucidation of its IgE-binding epitopes

Abstract

The major allergen (named Oct v 1) in the muscle of the octopus Octopus vulgaris was purified by gel filtration on Sephacryl S‐300, anion‐exchange fast protein liquid chromatography on Mono Q and reverse‐phase high‐pressure liquid chromatography on TSKgel Octadecyl‐4PW. In addition to the molecular mass, amino acid composition and cross‐reactivity with Tur c 1 (turban shell Turbo cornutus allergen), the determined partial amino acid sequence clearly demonstrated that Oct v 1 is tropomyosin, similar to the known molluscan and crustacean allergens. Using peptide fragments isolated from the lysylendopeptidase digest of Oct v 1, competitive enzyme‐linked immunosorbant assay inhibition experiments showed that IgE‐binding epitopes of Oct v 1 are contained in two peptides (77–112 and 148–160) in the central region and one peptide (269–281) in the C‐terminal region. In the peptide 77–112, the same sequence as the IgE‐binding epitope proposed for Cra g 1 (oyster Crassostrea gigas allergen) is recognized at 92‐105. Moreover, the peptide 148‐160 partly overlaps with the IgE‐binding epitopes suggested for Pen i 1 (shrimp Penaeus indicus allergen) and Pen a 1 (shrimp Penaeus aztecus allergen), and the peptide 269–281 with those for Tur c 1 and Pen a 1.

Seasonal study of the lipid composition in different tissues of the common octopus ( Octopus vulgaris )

“…Such aquatic food products are typically commercialised fresh, frozen or dried-salted, both at the artisan and industrial scales [18]. Previous compositional analyses on octopus have focused only on the investigation of phospholipids (PL) [19], collagen [20] and tropomyosin [21]. However, and due to increasing consumer demand, research scientists are paying more attention to this aquatic food product, especially to its growth patterns and to the effects of its sexual maturation on biochemical and compositional changes affecting food quality [22,23].…”

Sarcoplasmic Calcium-Binding Protein: Identification as a New Allergen of the Black Tiger Shrimp <i>Penaeus monodon</i>

“…So far, tropomyosin has been established at the molecular level as the major allergen of a number of crustaceans including shrimp [1,2,3,4], crayfish [5], lobster [5], hermit crab [4], crab [4, 6] and barnacle [7]. In addition, tropomyosin has also been identified as the major allergen of mollusks such as cephalopods [8,9,10], gastropods [11, 12] and bivalves [12] and as one of the allergens of house dust mites [13, 14] and cockroaches [15, 16]. Thus, it is currently accepted that tropomyosin is a cross-reactive panallergen of invertebrates [15,16,17,18,19,20].…”

Analysis of the Allergenic Epitopes of Tropomyosin from Mud Crab Using Phage Display and Site-Directed Mutagenesis

“…These peptides, excluding trypsin-cutting sites, were only part of the intact epitopes, and they also highly overlapped with previously reported allergenic shrimp TM epitopes. 17,29,30 Our previous studies also showed that the digestion products of TM still maintained the ability of sensitization. 35,36,43,44 This was the reason that TM had the ability to activate an allergic reaction after gastrointestinal digestion.…”