食品科学 ›› 2017, Vol. 38 ›› Issue (11): 1-5.doi: 10.7506/spkx1002-6630-201711001

• 基础研究 •    下一篇

牛乳α-乳白蛋白IgE线性表位的关键氨基酸识别

丛艳君,陈 澍,李 晔,于晓凤,李林峰   

  1. 1.北京工商大学食品学院,食品添加剂与配料北京高校工程研究中心,北京 100048;2.北京友谊医院皮肤科,北京 100050
  • 出版日期:2017-06-15 发布日期:2017-06-19

Identification of the Critical Amino Acids of IgE-Binding Epitopes in α-Lactalbumin

CONG Yanjun, CHEN Shu, LI Ye, YU Xiaofeng, LI Linfeng   

  1. 1. Beijing Higher Institution Engineering Research Center of Food Additives and Ingredients, College of Food Science, Beijing Technology and Business University, Beijing 100048, China; 2. Department of Dermatology, Beijing Friendship Hospital, Beijing 100050, China
  • Online:2017-06-15 Published:2017-06-19

摘要: α-乳白蛋白是引起牛乳过敏的主要过敏原之一。识别α-乳白蛋白作用表位及影响致敏性的关键氨基酸,对于揭示α-乳白蛋白致敏机理及低致敏乳制品的开发具有重要的意义。本研究采用固相合成技术合成α-乳白蛋白系列多肽,以牛乳过敏患者血清为探针,通过酶联免疫吸附分析法识别α-乳白蛋白的作用表位和关键氨基酸。结果表明:免疫球蛋白(immunoglobulins,Ig)E作用表位的氨基酸序列定位为aa1-15、aa6-20、aa46-60、aa71-85和aa101-115。α-乳白蛋白IgE作用表位关键氨基酸为第8位的缬氨酸、第9位的苯丙氨酸、第10位的精氨酸、第103位的酪氨酸、第105位的亮氨酸和第107位组氨酸。本研究可以为过敏原cDNA克隆以激活T细胞、降低IgE结合能力提供重要思路。

关键词: 牛乳过敏, α-乳白蛋白, 作用表位, 关键氨基酸

Abstract: α-Lactalbumin represents one of the major allergens causing cow milk allergy. The identification of the epitopes of α-lactalbumin and the critical amino acids for its allergenicity is of great significance for understanding the mechanism of action of α-lactalbumin and developing hypoallergenic dairy products. In this study, a series of peptides were synthesized by a solid phase method for the characterization of immunological epitopes and critical amino acids. The immunoglobulin (Ig) E-binding epitopes were immunolabeled with individual sera from cow milk-allergic patients as probes by enzyme linked immunosorbent assay (ELISA). Alanine scanning of immunodominant epitopes was used to identify the critical amino acids (aa). The results showed that IgE-binding epitopes were located within the sequences of aa1-15, aa6-20, aa46-60, aa71-85 and aa101-115. Our initial data revealed that Val8, Phe9, Arg10, Tyr103, Leu105 and His107 were the critical amino acids for IgE-binding epitopes. This study will provide the necessary information to alter the cDNA to encode a protein capable of activating milk-specific T cells, but with reduced IgE-binding capacity.

Key words: cow milk allergy, α-lactalbumin, epitope, critical amino acid

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