生物信息学研究豇豆胰蛋白酶抑制剂的致敏性  

Research the Allergenicity of Cowpea Trypsin Inhibitor Using Bioinfor-matic Analysis

作　　者：周催[1] 孙娜[1] 王翠燕[1] 孙璐[1] 车会莲[1] 

机构地区：[1]中国农业大学食品科学与营养工程学院,北京100083

出　　处：《农业生物技术学报》2013年第12期1473-1478,共6页Journal of Agricultural Biotechnology

基　　金：国家"十二五"转基因重大专项课题(No.2013ZX08011-006)

摘　　要：随着豇豆胰蛋白酶抑制剂基因（CpTI）近年来在棉花、水稻等农作物中的应用，CpTI在人类食物中的分布也日益广泛。作为一种外源蛋白，其致敏性越来越引起人们的关注，本研究对CpTI的潜在致敏性进行生物信息学分析，并与其他研究方法得到的结果进行比较，旨在进一步明确其潜在致敏性。在分析CpTI蛋白理化性质的基础上，使用DNAStar软件和Kolaskar-Tongaonkar在线服务器分别分析CpTI蛋白的抗原表位，同时使用致敏原在线数据库（Allergenonline）和致敏蛋白结构数据库（SDAP）中将CpTI氨基酸序列与已知致敏原序列进行比较分析其潜在致敏性。研究结果分析得到CpTI蛋白的抗原表位氨基酸区域可能为76~80，小于6个氨基酸，几乎不能形成抗原决定簇。另外，CpTI蛋白与已知致敏原中连续80个氨基酸的最高相似度为18.85%，没有发现CpTI具有与已知氨基酸序列完全相同的连续8个氨基酸。研究表明，抗原表位分析可以预测蛋白的免疫原性，而使用Allergenonline和SDAP数据库分析可以分析蛋白与已知致敏原之间的交叉反应性，从而预测其致敏性。采用这些方法对CpTI进行分析的结果显示，未发现其具有可形成抗原决定簇的抗原表位序列，与已知致敏原的相似度也没有达到产生交叉反应的程度。本研究显示，CpTI无致敏性或潜在致敏性很低，这将对使用生物信息学分析工具预测新型蛋白的潜在致敏性具有一定的参考意义。With the application of cowpea trypsin inhibitor gene（CpTI） in crops such as cotton and rice, distribution of CpTI in human food is increasingly widespread. As a foreign protein, the allergenicity of CpTI has aroused people’s concern. Recent years some web-based tools that integrate with databases of allergenic proteins could be used to improve our ability to predict allergenicity based on structural analysis. In this study, bioinformatic analysis methods were used to evaluate the potential allergenicity of CpTI and the outcome was then compared with results of other methods aimed to conform its potential allergenicity more clearly. Allergenonline, structure database of allergic protein（SDAP）, DNAStar software and Kolaskar-Tongaonkar online server were used to compare and analyze CpTI’s allergenicity and immunogenicity on the basis of analyzing its physical and chemical properties. The Allergenonline and SDAP database were used to predict the similarity of amino acid of CpTI with known allergens collected in the databases. The primary comparison methods included the identification of similar sequence that hold more than 35% in a known 80 amino acid sequence, and the existence of continue 6 or 8 amino acid that same as that in CpTI in known allergic sequences. Besides, the physical and chemical properties containing isoelectric point, stability coefficient, coefficient of fat, existence of signal peptide were analyzed using online servers of ProtPara （http：//web.expasy.org/protparam/）, SignakIP4. （http：//www.cbs.dtu.dk/services/SignalP/） and TMHMM （http：//www.cbs.dtu.dk/services/TMH MM-2.0/）. The result of properties analysis showed that CpTI’s theoretical isoelectric point was 4.96, unstable and fat coefficient were 95.57 and 33.68 respectively, and did not contain signal peptid. So we conclude that the CpTI is a protein of unstable and hydrophobi. Bioinformatics analysis showed that CpTI’s antigen epitope area of amino acid was 76~80, which was less than 6 amino acids and almost

关 键 词：豇豆胰蛋白酶抑制剂 潜在致敏性评价 生物信息学分析 

分 类 号：S637[农业科学—蔬菜学]