辐照对虾过敏原生化性质及抗原性的影响

发布时间：2018-06-15 22:03

本文选题：虾过敏原 + 辐照　；参考：《中国农业科学院》2007年硕士论文

【摘要】： 食物过敏作为食源性疾病的一种已引起了人们的普遍关注。根据流行病学调查，美国每年约有2％～2.5％的人发生食物过敏，儿童及婴幼儿的发病率约5％～8％。澳洲每年有600例过敏性疾病发生，并且在2004年食品企业的召回产品中，过敏食品比例就达47％。据不完全统计，我国的发病率也较高。近年来，有关食源性虾过敏的报道屡见不鲜。在联合国粮农组织提出的八大类引起过敏的食物之中，虾与蟹等甲壳类动物及其制品是重要的一类。最近韩国、德国以及加拿大等国报道，辐照技术可促进过敏原蛋白质的降解、交联和分子构象的改变，破坏其抗原决定簇，有可能成为降低食物过敏反应的技术手段。为了探索过敏原辐照脱敏的机理，本研究以中国海虾过敏原TM(Tropomyosin)为研究对象，对不同存在状态的过敏原(提取液、冻干粉和全虾)做辐照处理，分析其辐照的生化效应；利用电泳技术纯化的微量过敏原免疫动物制备高效价高特异性抗体，在此基础上分析其辐照免疫学效应，探讨过敏原的辐照免疫学分子机理，为我国食品辐照脱敏技术的研究提供理论依据。虾是引起过敏反应的重要食物之一，研究发现原肌球蛋白(Tropomyosin,TM)是虾中一种主要过敏原，这是一种分子量为36kDa的热稳定性蛋白。据Lee YK和Myung-Woo Byun等报道辐照可破坏其抗原表位，降低其致敏性。本研究利用过敏原的热稳性及低盐离子溶液中可溶性，成功地对过敏原作了常规提纯。在此基础上研究了不同剂量的辐照处理对不同存在状态的过敏原TM的分子结构、疏水性、浊度等生化性质的影响，证实辐照改变了过敏原TM水溶性、疏水性，过敏原分子发生了解聚、交联等反应，进而改变了其生物学特性。为了进一步了解辐照对过敏原致敏性的影响，在比较利用不同方法提纯的过敏原蛋白质做免疫原免疫动物制备抗体的优劣前提下，设计利用SDS-PAGE纯化的虾过敏原(TM)成功地制备出过敏原TM的高效价高特异性多克隆抗体，结合人血清过敏原抗体IgE，研究了不同剂量的辐照处理对不同存在状态的过敏原与患者特异性血清抗体IgE及多抗的亲和性的影响。结果发现：沸水处理后过敏原溶液与患者特异性血清抗体IgE仍具有很强的结合力，这证实了前人关于TM具有很强的热稳定性报道；虾过敏原(TM)经辐照处理后，TM与患者特异性血清抗体IgE及鼠源多抗(IgG)的免疫亲和力随着辐照剂量的增加而降低，表明辐照改变了过敏原的生化特性及抗原性，致敏性降低，并发现TM的溶液状态要比固体状态和活体状态对辐照处理敏感。研究证明辐照改变了过敏原TM的空间构象，从而改变了过敏原的水溶性、疏水性等生物学特性，进而使过敏原分子发生解聚、交联、裂解等化学反应，从而改变或者破坏过敏原抗原表位，降低了TM的致敏性。
[Abstract]:Food allergy as a food-borne disease has aroused widespread concern. According to an epidemiological survey, about 2. 5% of people in the United States develop food allergies each year, and about 5% of children and infants develop food allergies. There are 600 cases of allergic diseases in Australia each year, and the proportion of allergic food products recalled by food companies reached 47% in 2004. According to incomplete statistics, the incidence of disease in China is also high. In recent years, food-derived shrimp allergies are frequently reported. Among the eight allergenic foods proposed by FAO, crustaceans such as shrimps and crabs and their products are important. Recently, Korea, Germany and Canada reported that irradiation technology can promote the degradation of allergen proteins, cross-linking and molecular conformation changes, destroy its antigenic determinants, and may become a technical means to reduce food allergic reactions. In order to explore the mechanism of irradiation desensitization of allergen, the allergen (TMN Tropomyosin) was studied in this study. The allergens (extract, freeze-dried powder and whole shrimp) were treated by irradiation, and the biochemical effects of irradiation were analyzed. High titer and high specific antibodies were prepared by immunizing animals with microallergens purified by electrophoretic technique. On the basis of this, the effects of irradiation immunology were analyzed, and the molecular mechanism of irradiation immunology of allergens was discussed. It provides a theoretical basis for the research of food irradiation desensitization technology in China. Shrimp is one of the most important foods causing allergic reactions. Tropomyosin TMTM is a major allergen in shrimp, which is a 36 kDa thermostable protein. Lee YK and Myung-Woo Byun have reported that irradiation can destroy their epitopes and reduce their sensitivities. In this study, the allergy was successfully purified by using the thermostability of the allergen and the solubility of the allergen in low salt ion solution. On this basis, the effects of different doses of irradiation on the molecular structure, hydrophobicity, turbidity and other biochemical properties of allergen TM in different states were studied. It was proved that irradiation changed the water solubility and hydrophobicity of allergen TM. The depolymerization, crosslinking and other reactions of allergen molecules have changed their biological characteristics. In order to understand the effect of irradiation on allergen sensitivities, we compared the advantages and disadvantages of using different methods to purify allergen proteins to prepare antibodies in immunogenic immunized animals. The high titer and high specificity polyclonal antibody of allergen TM was successfully prepared by SDS-PAGE purified shrimp allergen TMN. Combined with human serum allergen antibody IgE, the effects of different doses of irradiation on the affinity of allergens in different states to patients' specific serum antibody IgE and polyantibodies were studied. The results showed that: after boiling water treatment, the allergen solution still had strong binding ability with patient specific serum antibody IgE, which confirmed that previous reports on TM had strong thermal stability. The immunological affinity of TM with specific serum antibody IgE and mouse polyantibody IgG decreased with the increase of irradiation dose, indicating that irradiation changed the biochemical characteristics and antigenicity of the allergen, and the sensitivities were decreased, and the immunological affinity of TM with the specific serum antibody IgE and mouse polyclonal antibody IgG) decreased with the increase of irradiation dose, which indicated that irradiation changed the biochemical characteristics and antigenicity of the allergen. It is also found that TM solution state is more sensitive to irradiation than solid state and living state. It has been proved that irradiation changes the spatial conformation of allergen TM, thus changes the biological properties of allergen, such as water solubility and hydrophobicity, thus causing chemical reactions such as depolymerization, crosslinking and cracking of allergen molecules. Thus, the allergen epitopes were changed or destroyed, and the sensitivities of TM were decreased.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2007
【分类号】：R392

【引证文献】