梭子蟹变应原的分离、纯化与鉴定

目的：对梭子蟹（Portunus pelogicus（Linnaeus））变应原进行分离,鉴定其主要及次要变应原,采用蛋白纯化技术获取梭子蟹天然的主要变应原并进行鉴定,为标准化变应原疫苗的研制提供理论依据.方法：取常规方法制备梭子蟹浸出液,经SDS-PAGE分离,测定各组分的相对分子量;同时用26例对蟹过敏的病人血清进行Western blot,鉴定其主要及次要变应原;利用快速制备液相色谱（FPLC）纯化技术（凝胶过滤层析和离子交换层析）获取主要变应原并作鉴定.结果：SDS-PAGE显示梭子蟹有19条可辨蛋白带,分子量在13 000～90 000之间,其中主带有9条,分子量是20 900、24 200、27 100、29 200、33 700、38 900、48 700、74 700、89 100;Western blot结果表明,26例蟹过敏患者血清全部呈阳性反应,浸出液中共有5条致敏条带,其中分子量在74 400、48 700的是主要变应原,阳性反应率均为100%;纯化后获取了74400、48700的主要变应原;经过免疫鉴定证实其具有免疫活性.结论：梭子蟹74 400和48 700的变应原为主要变应原,层析技术可以对分子量为74400和48700的主要变应原成分进行纯化.

Purification, identification and characterization of the major allergen from Linnaeus

Objective:To purify and characterize the major antigenic components of sand swimming crab,and provide theoretical evidences for the research of standardization of allergenic vaccine.Methods:The crude extract of Linnaeus was prepared using classical method, and electrophoresis of SDS-PAGE was used to separate the proteins of each group. The allergen proteins of 26 crab were identified using Western blot. To distinguish between the primary allergen proteins and secondary allergen proteins, FPLC(Gel Chromatography and ion exchange chromatography) was used to filtrate and identify the allergen protein.Results:SDS-PAGE analysis revealed that sand swimming crab proteins were composed of at lease 9 discrete protein bands, which molecular weight ranging from 13 000 to 90 000. Major bands were of 20 900, 24 200, 27 100, 29 200, 33 700, 38 900, 48 700, 74 700, 89 100 respectively. Western blot assay indicated that the crude extract reacted with sera obtained from 26 crab allergenic subjects and contained 5 allergen bands altogether, and the bands of 74 400 and 48 700 were the major allergenic components. The positive rates of the two major allergen proteins were both 100%, indicating the allergenic components maintained the immunocompetence after yielding from chromatography.Conclusion:The 74 400 and 48 700 bands are the major allergens of sand swimming crab. The major allergen proteins can be purified by chromatography.