日本血吸虫类毒过敏原蛋白的筛选及其生物信息学分析

Screening and bioinformatic analysis of venom allergen-like protein 2 in Schistosoma japonicum

目的从日本血吸虫基因组中筛选鉴定类毒过敏原基因,并分析其编码蛋白的生物学特性。方法基于日本血吸虫基因组筛选出类毒过敏原基因序列,并进行PCR验证;通过生物信息学方法分析该基因编码蛋白的结构特征,包括疏水区、跨膜区、信号肽及结构域,以及编码蛋白质的二级、三级结构及其抗原表位;利用Clustal-X 2.1软件对其编码的氨基酸序列进行同源比对;利用MEGA X软件构建系统发育树;通过STRING数据库对其蛋白互作网络进行预测。结果从日本血吸虫基因组中筛选鉴定出1条具有完整编码区的类毒过敏原基因序列,其长度为486 bp,编码161个氨基酸;预测其编码蛋白相对分子质量为18.93891×10^5,为分泌蛋白;其5′区域包含一个信号肽,无跨膜区,推测具有7个抗原表位。以STRING在线数据库中线虫蛋白互作网络信息作为参考,对血吸虫类毒过敏原蛋白互作网络进行预测,共鉴定出包括10个蛋白在内的16个互作关系。结论从血吸虫基因组中筛选出1条类毒过敏原蛋白基因,生物信息学方法预测其为分泌蛋白,并含有一定数量的抗原表位,为该蛋白作为候选疫苗和诊断抗原提供了分子基础。

Objective To identify genes coding for venom allergen-like protein 2(VAL-2)by screening Schistosoma japonicum genome data and to analyze the biological characteristics of the coding protein.Methods Annotation of the S.japonicum genome was performed,and the identified allergen gene was verified using a polymerase chain reaction(PCR).The structural characteristics of the protein encoded by the gene were analyzed bioinformatically,including its hydrophobic regions,transmembrane regions,signal peptides,domains,secondary and tertiary structures,and epitopes.The software Clustal-X 2.1 was used to analyze the homology of the encoded amino acid sequence.The phylogenetic tree was constructed using the software MEGA X.Then the protein interaction network of S.japonicum was predicted using the STRING database.Results The sequence of the allergen gene with complete coding regions was identified from the genome of S.japonicum.The sequence is 486 bp in length and codes for 161 amino acids.The encoding protein was predicted to be a secretory protein of 18.93891×10^5 that contains 7 epitopes.Information on the protein interaction network of Schistosoma allergen genes was explored while referencing the STRING database to predict the related protein interaction network.In total,16 protein interaction relationships were identified and they included 10 proteins.Conclusion An S.japonicum allergen gene that encodes a secreted protein with epitopes was identified from the Schistosoma genome.These results provide a theoretical basis for further research on vaccines or potential molecules to serve as diagnostic antigen.