结核分枝杆菌BfrB蛋白的生物信息学分析

Bioinformatic analysis of the Rv3841 gene from Mycobacterium tuberculosis

目的应用生物信息学软件分析及预测结核分枝杆菌Rv3841基因编码蛋白BfrB的结构与功能。方法从NCBI数据库中获取Rv3841基因及其编码序列;利用ProtParam及ProtScale预测BfrB蛋白的理化性质及亲疏水性;应用SignalP 4.0及TMHMM分析BfrB蛋白的信号肽及跨膜区;应用SOPMA及SWISS MODEL工具分析蛋白的二级结构,建立三级结构模型;利用Bepired1.0、ABCpred及SYFPEITHI、NetMHCIIpan预测蛋白的细胞表位,寻找最佳B细胞与T细胞抗原表位。结果 Rv3841编码的BfrB蛋白具有181个氨基酸残基,平均疏水系数为-0.277,为亲水性蛋白。BfrB蛋白无信号肽序列及跨膜区域,二级结构中α螺旋约占65.19%,β折叠6.63%,β折角4.97%,无规则卷曲23.2%。预测的B细胞、CTL细胞及Th细胞抗原表位分别为7、9、11个。结论生物信息学方法预测BfrB蛋白为亲水性蛋白,具有潜在的B、T细胞抗原表位,可作为研发新的结核病疫苗靶标。

Objective To use bioinformatic software to analyze and predict the structure and function of BfrB,which is coded for by the Rv3841 gene of Mycobacterium tuberculosis. Methods The Rv3841 gene and the amino acid sequence that it encodes were obtained from the NCBI database.ProParam and ProtScale were used to predict the physicochemical properties and hydrophobicity-hydrophilicity of the BfrB protein.SignalP 4.0 and TMHMM were used to analyze the signal peptide and transmembrane region.SOPMA and SWISS MODEL were used to analyze the secondary structure and build tertiary model of BfrB.ABCpred,SYFPEITHI,NetMHCIIpan 3.1,and BepiPred 1.0 were used to predict cell epitopes of the protein in order to search for optimal B-cell and T-cell epitopes. Results The Rv3841 gene of M.tuberculosis codes for the protein BfrB,which consists of 181 amino acid residues.The average hydrophobicity index of the protein was-0.277,and BfrB might be a hydrophilic protein.The protein has no signal peptides or transmembrane structure.α-helices account for 65.19% of the secondary structure of the BfrB protein,β-folds account for 6.63%,β-corners account for 4.97%,and random coils account for 23.2%.The BfrB protein has 7 potential B-cell epitopes,9 CTL cell epitopes,and 11 Th-cell epitopes. Conclusion Bioinformatics predicted that BfrB was a hydrophilic protein and that it possessed potential B-and T-cell epitopes.The BfrB protein could be used as a target for new tuberculosis vaccines.