多房棘球绦虫亮氨酰氨肽酶抗原表位的生物信息学预测

Bioinformatic prediction of epitopes in the Echinococcus multilocularis leucyl aminopeptidase antigen

目的分析鉴定多房棘球绦虫亮氨酰氨肽酶(Echinococcus multilocularis leucyl aminopeptidase,EmLAP)蛋白质二级结构并预测其优势抗原表位。方法从GenBank中获得多房棘球绦虫亮氨酰氨肽酶氨基酸序列,并通过生物信息学软件SOPMA分析多房棘球绦虫亮氨酰氨肽酶的蛋白质二级结构特征。进一步通过生物信息学软件IEDB、Syfpeithi、Bcepred、ABCpred预测分析多房棘球绦虫亮氨酰氨肽酶潜在的T细胞及B细胞抗原表位。结果分析出多房棘球绦虫亮氨酰氨肽酶的蛋白质二级结构中α螺旋占比为45.42%、β折叠占比为16.57%、β转角占比为8.58%、无规则卷曲占比为29.43%。预测出亮氨酰氨肽酶具有9个T细胞潜在优势抗原表位,分别为L65-73、L75-84、L174-186、L233-240、L301-308、L333-343、L392-400、L445-454、L482-490;预测出多房棘球绦虫亮氨酰氨肽酶具有20个B细胞潜在优势抗原表位,分别为L13-22、L39-47、L75-84、L98-110、L146-154、L174-186、L183-191、L233-240、L247-254、L281-288、L295-306、L319-328、L330-337、L339-347、L392-400、L397-410、L421-428、L464-473、L493-504、L504-512。结论通过使用生物信息学软件预测出多房棘球绦虫亮氨酰氨肽酶存在有潜在的优势抗原表位,分别为9个T细胞抗原表位和20个B细胞抗原表位,为后续多房棘球绦虫相关亮氨酰氨肽酶的抗原性研究和多表位疫苗的研制奠定了基础。

Objective The present study aims to predict the secondary structure and the T-cell and B-cell epitopes for the Echinococcus muhilocularis leucyl aminopeptidase （EmLAP） antigen in order to reveal the dominant epitopes of the antigen. Methods The secondary structure of the protein was analyzed using SOPMA server. The T-cell and B-cell epitopes of EmLAP were predicted using IEDB, Syfpeithi, Bcepred and ABCpred online software. Results The Alpha helix accounted for 45.42%, the Extended strand accounted for 16.57%, the Beta turn accounted for 8.58% and the Random coil accounted for 29.43% of the secondary structure of the EmLAP ,respectively.Fol- lowing bioinformatic analysis, numerous distinct antigenic epitopes of EmLAP were identified. The high - scoring T-cell epitopes were located at positions L65 - 73, L75 - 84, L174 - 186, L233 - 240, L301 - 308, L333 - 343, L392-400, IA45-45 and L482-490 ;whilst the likely B-cell epitopes were located at positions L13-22, L39-47, L75- 84, L98-110, L146-154, L174-186, L183-191, L233 - 240, L247- 254, L281 - 288, L295 - 306, L319- 328, L330-337, L339-347, L392-400, L397-410, L421-428, L464-473, L493-504 and L504-512. Conclusions Nine T-cell and twenty B-cell dominant epitopes of the EmLAP antigen were revealed by the bioinformatic methods which may he useful for the development of a dominant epitope vaccine.