统计学筛选电脑预测的人H5N1毒株核蛋白B细胞表位

目的 预测并筛选人禽流感H5N1毒株核蛋白(NP)的B细胞抗原表位.方法 采用DNAStar Lasergene 7.1软件,进行人禽流感H5N1毒株NP基因核苷酸序列分析.采用Kyte-Doolittle的亲水性方法、Emini方法和Jameson-Wolf抗原指数方法,辅以对NP的二级结构中的柔性区域的分析,采用SPSS13.0进行聚类、相关和四分位数分析,建立一种统计学筛选程序,预测H5N1病毒NP的B细胞表位,并对毒株A/GD/01/06(H5N1)的NP变异进行评价.结果 预测并筛选最有可能的B细胞表位为位于NP的N端317～326、452～457、467～473、367～370、491～498、375～378、171～177、48～53、245～250、76～104肽段等.A/GD/01/06(H5N1)的NP通过氨基酸第370位(N370S)位点置换,增加一个糖基化位点(NES368-370)并改变NP的特性.结论 用多参数预测并统计学筛选H5N1毒株NP的B细胞表位,可以为分子免疫学研究和药物筛选提供依据.A/GD/01/06(H5N1)毒株NP氨基酸第370位(N370S)位点置换改变其抗原性,但抗原表位大小未变(SNEN367-370).

Statistical screening of the B-cell epitopes for the nucleoprotein of human H5N1 virus predicted by computerization

Objective To predict and screen the B-cell epitopes on nucleoprotein(NP)of human avian H5N1 virus strain.Methods As NP nucleotide sequences of strain A/GD/01/06(H5N1)were sequenced,B-cell epitopes were predicted by the analysis of the flexible regions of secondary structure for NPprotein and by screening on B-cell epitopes for NP protein with methods of Hydrophilicity Plot by KyteDoolittle,Surface Probability Plot by Emini,and Antigenic Index by Jameson-Wolf.Then a screening method was established by Hierarchical cluster,Bivariate correlate and Quartiles in SPSS13.0.and the variation of amino acids in NP protein was appraised in epitope prediction.Resuits The computer-predicted most possible epitopes for NP protein were located within or nearby its N-terminal 317-326,452-457,467-473,367-370,491-498,375-378,171-177,48-53,245-250.76-104 and so on.NP protein in A/GD/01/06(H5N1)increased a glycoprotein domain(NES368-370)by the substitution of N370S and changed the bio-features.Conclusion Stepwise prediction of the B-cell epitopes for the NP protein based on multiple parameters is helpful for the molecular-immunology and drug-screening,and the substitution of N370 S in NP of A/GD/01/06(H5N1)varied its antigenicity but didn't change the epitope size(SNEN367-370).