牛乳α-乳白蛋白免疫球蛋白G线性表位的关键氨基酸识别  

Characterization of Critical Amino Acids in Linear Immunoglobulin G Epitopes of α-Lactalbumin in Cow Milk

作　　者：丛艳君 李晔 刘家琦 陈澍 于晓凤 李林峰[2] CONG Yanjun;LI Ye;LIU Jiaqi;CHEN Shu;YU Xiaofeng;LI Linfeng(Beijing Higher Institution Engineering Research Center of Food Additives and Ingredients,School of Food and Chemical Engineering,Beijing Technology and Business University,Beijing 100048,China;Department of Dermatology,Beijing Friendship Hospital,Beijing 100050,China)

机构地区：[1]食品添加剂与配料北京高校工程研究中心,北京工商大学食品学院,北京100048 [2]北京友谊医院皮肤科,北京100050

出　　处：《食品科学》2018年第7期195-200,共6页Food Science

基　　金：国家自然科学基金青年科学基金项目(31101236);北京市自然科学基金项目(6132004);北京市科技新星计划项目(Z131102000413005)

摘　　要：α-乳白蛋白是牛乳中的主要过敏原,开展α-乳白蛋白表位定位及氨基酸特性研究可深入了解过敏原的致敏机理,有助于更好地认识免疫球蛋白G(immunoglobulin G,Ig G)在乳过敏反应中的作用,为制备低过敏乳制品提供理论指导。本研究采用丙氨酸免疫表位扫描技术识别α-乳白蛋白的关键氨基酸,即用牛乳过敏患者血清中Ig G识别α-乳白蛋白系列合成的多肽,筛选作用表位,然后用丙氨酸依次取代作用表位的氨基酸合成新的多肽,以牛乳过敏患者血清池为抗体识别关键氨基酸。结果表明:α-乳白蛋白Ig G作用表位的氨基酸序列定位为aa6~20、aa21~35、aa36~50和aa86~100;关键氨基酸为第9位的苯丙氨酸、第15位的亮氨酸、第24位的脯氨酸、第26位的色氨酸和第32位的组氨酸。α-Lactalbumin is one of the major allergens in cow milk.Characterizing the critical amino acids in the epitopes ofα-lactalbumin is of great significance for the understanding of the role of immunoglobulin G(IgG)in milk allergy and the development of hypoallergenic dairy products.In this study,the alanine scanning of immunodominant epitopes was used to identify the critical amino acids.First,a series of peptides based on the sequence ofα-lactalbumin were identified with IgG in individual sera from cow milk-allergic patients by enzyme-linked immunosorbent assay(ELISA).Then,new peptides were synthesized by sequential replacement of the amino acids acting on the epitopes with alanine,and the critical amino acids were identified with serum pool from cow milk-allergic patients by ELISA.The results showed that IgG-binding epitopes were located in the sequences of aa 6–20,aa 21–35,aa 36–50 and aa 86–100.Our data revealed Phe9,Leu15,Pro24,Trp26 and His32 were the critical aa in the IgG-binding epitopes.

关 键 词：牛乳过敏 Α-乳白蛋白 免疫球蛋白G作用表位 关键氨基酸 

分 类 号：TS252.1[轻工技术与工程—农产品加工及贮藏工程]