Reese G, Ayuso R, Lehrer S B
Section of Allergy and Clinical Immunology, Tulane University School of Medicine, New Orleans, LA, USA.
Int Arch Allergy Immunol. 1999 Aug;119(4):247-58. doi: 10.1159/000024201.
Among food allergens, crustaceans, such as shrimp, crab, crawfish and lobster, are a frequent cause of adverse food reactions in allergic individuals. The major allergen has been identified as the muscle protein tropomyosin. This molecule belongs to a family of highly conserved proteins with multiple isoforms found in both muscle and nonmuscle cells of all species of vertebrates and invertebrates. Its native structure consists of two parallel alpha-helical tropomyosin molecules that are wound around each other forming a coiled-coil dimer. Allergenic tropomyosins are found in invertebrates such as crustaceans (shrimp, lobster, crab, crawfish), arachnids (house dust mites), insects (cockroaches), and mollusks (e.g. squid), whereas vertebrate tropomyosins are nonallergenic. Studies of cross-reactivities among crustaceans and the high degree of sequence identity among them suggest that tropomyosin is probably the common major allergen in crustaceans. Furthermore, immunological relationships between crustaceans, cockroaches and housedust mites have been established and may suggest tropomyosin as an important cross-sensitizing pan allergen.
在食物过敏原中，甲壳类动物，如虾、蟹、小龙虾和龙虾，是过敏个体食物不良反应的常见原因。主要过敏原已被鉴定为肌肉蛋白原肌球蛋白。这种分子属于一类高度保守的蛋白质家族，在所有脊椎动物和无脊椎动物的肌肉细胞和非肌肉细胞中都发现有多种异构体。其天然结构由两个相互缠绕的平行α-螺旋原肌球蛋白分子组成，形成一个卷曲螺旋二聚体。致敏原性原肌球蛋白存在于无脊椎动物中，如甲壳类动物（虾、龙虾、蟹、小龙虾）、蛛形纲动物（屋尘螨）、昆虫（蟑螂）和软体动物（如鱿鱼），而脊椎动物的原肌球蛋白则无致敏性。对甲壳类动物之间交叉反应性的研究以及它们之间高度的序列同一性表明，原肌球蛋白可能是甲壳类动物中常见的主要过敏原。此外，甲壳类动物、蟑螂和屋尘螨之间的免疫关系已经建立，这可能表明原肌球蛋白是一种重要的交叉致敏泛过敏原。
