【摘要】 目的:了解美洲大蠊变应原Per a 2的分子生物学特征。方法:从Genbank中获得Per a 2的核酸序列,用ExPaSy、EBI和NCBI网站的在线软件推导出编码氨基酸序列及其理化性质、空间结构、功能位点,并在Blastp比对后选择不同物种同源序列计算相似率、构建分子进化树。结果:Pera2由351个氨基酸细戍,分子量为38119Da、等电点为4.90、分子式为C1217H1825N285O297S18,为细胞外疏水性蛋白、属于肽酶a家族,信号肽位于1～20氨基酸处,三个跨膜螺旋区域依次位于1～19aa、51～78aa、282～300aa处;二级结构由α-螺旋(9.4%)、β延伸(28.49%)、随机线圈(62.11%)组成;美洲大蠊和德国小蠊相似率为55%、与马德拉蜚蠊相似率为51%,三者在Pera2与不同物种的同源序列构建的分子进化树中聚成一簇。结论:通过对Per a 2的生物信息学分析获得了该变应原分子特征,为进一步研究奠定基础。更多还原

【Abstract】 Objective:To investigate the molecular characteristics of the major allergens of Periplaneta americana Per a 2. Methods From Genbank,nucleotide sequence of Per a 2 was obtained;subsequently amino acid sequence,physico-chemical prop- erties,spatial structure and molecular evolution were analyzed by online software in ExPasy,EBI and NCBI web server.Results Per a 2 was made up of 351 amino acids with molecular weight 38119 Da and pⅠ4.90,and through bioinformatics analysis,the extra- cellular protein was demonstrated to be hydrophobicity with a cleavage site between positions 20 and 21.Secondary structure analy- sis revealed that HBsAg from China contained an alpha helix(9.4%),an extended strand(28.49%)and a random coil(62.11%). The similarity between Periplaneta Americana and Blattela germanica is 55%,while that between Periplaneta Americana and Leu- cophaea maderae is 51%,and Periplaneta americana clustered with Blattela germanica and Leucophaea maderae in polygenetic tree. Conclusion In this study,molecular characteristics of Per a 2 were obtained by bioinformatics software,which provides scientific proof for recombinant allergens.更多还原