HIV-1 gp41蛋白的主要特性及B/T细胞表位预测

Characteristics and prediction of B- and T-cell epitopes of the gp41 protein of HIV-1

目的采用生物信息学方法分析HIV-1 gp41跨膜糖蛋白的基因序列及其编码蛋白的结构特征,并预测可能的B/T细胞表位,为艾滋病疫苗及多肽药物开发提供理论依据。方法从NCBI GenBank数据库获取gp41基因及其编码蛋白序列,综合运用ExPASy ProtParam tool、SOPMA、TMpred、Motifscan、ABCpred、Bepipred、CTLPred和IEDB等在线软件分别预测其低级结构、跨膜区、翻译后修饰位点、B/T细胞表位。结果 HIV-1 gp41基因ORF长度为666 bp,编码222个氨基酸。该gp41蛋白共3 627个原子,相对分子质量为25.642 5×10~3,分子式为C_(1164)H_(1815)N_(317)O_(325)S_6。理论等电点为8.60,是稳定的疏水性蛋白。gp41蛋白具有无规则卷曲55个,占24.77%;13个翻译后修饰位点,存在N-糖基化、酪蛋白激酶Ⅱ磷酸化、N-酰胺化、蛋白激酶C磷酸化等修饰。gp41蛋白N-末端存在跨膜螺旋区,分别位于第2-20,80-97和171-192位氨基酸处,这3个螺旋区的总评分为4 614。预测gp41蛋白含有23个B细胞抗原表位,优势表位依次是87-102、93-108、113-128、78-93、151-166等;含有NKTYKEIWD、VERYLRDQR和EPDRPERIE 3个优势CTL细胞表位,分别位于第103-111、70-78、213-221位氨基酸处。结论预测gp41蛋白的B/T细胞表位进行预测,可为艾滋病疫苗及多肽药物的开发提供了理论依据。

Objectives To analyze the characteristics of the gp41 gene sequence and protein structure of HIV-1 CRF07BC and to predict its B-and T-cell epitopes using bioinformatics in order to lay a foundation for the research and development of AIDS vaccines and peptide-based drugs.Methods The gene sequences and the amino acid sequences of gp41 were obtained from NCBI’s GenBank database.The biological properties of the gp41 protein were analyzed,and its primary structure,transmembrane regions,post-translational modification sites,and B-and T-cell epitopes were predicted using the software ExPASy ProtParam tool,SOPMA,TMpred,Motifscan,ABCpred,Bepipred,CTLPred,and IEDB.Results The ORF of the gp41 gene is 666 bp in length,and it encodes 222 amino acids.It has 3,627 atoms,a relative molecular mass of 25.642 5×103,and its molecular formula is C1164H1815N317O325S6.The isoelectric point(PI) of the gp41 protein is 8.60,and it is a stable and hydrophobic protein.The gp41 protein has 55 random coils,which account for 24.77% of its structure.It also has 13 post-translational modification sites,including 4 N-glycosylation sites,2 Casein kinase II phosphorylation sites,4 N-myristoylation sites,and 3 protein kinase C phosphorylation sites.It has transmembrane regions located at the N-terminus at amino acids 2-20,80-97,and 171-192.These 3 transmembrane helical regions have a total score of 4,614.The predicted gp41 protein contains 23 B-cell antigen epitopes at amino acids 87-102,93-108,113-128,78-93,and 151-166.Three CTL epitopes-NKTYKEIWD,VERYLRDQR,and EPDRPERIE-at amino acids 103-111,70-78,and 213-221 are the predominant epitopes.Conclusion The characteristics and B-and T-cell epitopes of the gp41 protein were successfully predicted.These findings provide a theoretical basis for developing AIDS vaccines and peptide-based drugs.