结核分枝杆菌PE_PGRS33蛋白的生物信息学分析

Bioinformatic analysis of the protein PE_PGRS33 of Mycobacterium tuberculosis

目的应用生物信息学方法对结核分枝杆菌Rv1818c基因编码蛋白PE_PGRS33的结构和功能进行预测分析。 方法自GenBank数据库中提取Rv1818c基因相关基因信息;运用ProtParam及ProtScale预测其编码的PE_PGRS33蛋白理化性质和亲疏水性;分别运用NetPhos、TMHMM分析PE_PGRS33的磷酸化位点、跨膜螺旋;利用SOPMA、SWISS、MODEL分析PE_PGRS33蛋白的二级结构并建立三级结构模型;利用Bepired、ABCpred及SYFPEITHI预测PE_PGRS33蛋白的B细胞与T细胞表位。 结果Rv1818c基因编码的PE_PGRS33蛋白含有498个氨基酸残基,疏水系数0.425,为疏水性蛋白。PE_PGRS33含有7个磷酸化位点,不存在跨膜区域,二级结构以无规卷曲为主(占50.20%),结构较松散。利用SWISS-MODEL建构建出PE_PGRS33蛋白的三级结构。PE_PGRS33蛋白含有27个B细胞抗原表位,数个T细胞优势表位。 结论PE_PGRS33蛋白是结核分枝杆菌的重要表面暴露蛋白,与结核分枝杆菌的潜伏感染密切相关。生物信息学预测该蛋白含有多个抗原表位,可作为结核治疗的潜在分子靶标。

Objective To bioinformatically predict the structure and function of the protein PE_PGRS33encoded by the Rv1818cgene of Mycobacterium tuberculosis. Methods Gene-related information on the Rv1818cgene was obtained from the GenBank database,and its open reading frames were analyzed using ORF Finder.ProtParam and ProtScale were used to predict the physicochemical and hydrophilic properties of the PE_PGRS33protein.The phosphorylation site, transmembrane region,and post-translational modification sites of PE_PGRS33were analyzed using NetPhos and TMHMM. The secondary structure of the PE_PGRS33protein was analyzed using SOPMA,SWISS,and MODEL,and the tertiary structure was modeled.Bepipred,ABCpred,and SYFPEITHI were used to predict the B-cell and T-cell epitopes of the PE_PGRS33protein.Protein interaction with PE_PGRS33was predicted using the STRING database. Results The Rv1818cgene contains 6open reading frames,it has a total length of 1,497bp,and the PE_PGRS33protein that it encodes contains 498amino acid residues,with glycine(41.16%)and alanine(20.08%)accounting for the largest proportion of those residues.Its hydrophobicity index is 0.425,and it is predicted to be a relatively stable hydrophobic protein. PE_PGRS33contains 7phosphorylation sites,including 5threonine phosphorylation sites and 2serine phosphorylation sites.There is no transmembrane region,and the secondary structure is dominated by random coils(50.20%),with a loose structure.The tertiary structure of the PE_PGRS33protein was modeled using SWISS-MODEL.The PE_ PGRS33protein contains 27B-cell epitopes and several dominant T-cell epitopes.According to the STRING database,the PE_PGRS33protein was predicted to interact with proteins such as ilvG,Rv1819c,and secA2. Conclusion The PE_ PGRS33protein is an important surface-exposed protein of M.tuberculosis and is closely related to latent infection with M.tuberculosis.Bioinformatics predicted that PE_PGRS33contains multiple epitopes that can serve as potential molecular targets for treatment of tuberculosis.