结核分枝杆菌Rv1772蛋白的结构与功能分析

Structural and functional analysis of Rv1772 protein in Mycobacterium tuberculosis

目的对结核分枝杆菌(MTB)Rv1772蛋白的结构及功能进行生物信息学分析。方法从美国国立生物技术信息中心获取MTB的Rv1772基因信息,利用生物信息学软件分析Rv1772蛋白结构及功能。结果Rv1772蛋白的相对分子质量为10896.28,由103个氨基酸构成,其脂肪指数为77.96,不稳定系数为43.98(>40),属不稳定蛋白。Rv1772蛋白的亲水性总平均值为—0.105,溶解度为0.49。Rv1772蛋白仅有胞内域和胞外域2个部分,无跨膜区,其可能为非跨膜蛋白。Rv1772蛋白无信号肽[D值为0.112(<0.45)],为可溶性蛋白,定位于细胞质。Rv1772含6个丝氨酸磷酸化位点,5个苏氨酸磷酸化位点,其可能参与调控MTB感染中对宿主细胞间信号的传导。Rv1772蛋白二级结构由α-螺旋(52.43%)、β-折叠(9.71%)、β-转角(4.85%)和无规则卷曲(33.01%)组成。Rv1772蛋白含较多的α-螺旋结构,其可能有多个B细胞抗原表位。Rv1772蛋白含3个IFN-γ诱导阳性的HTL抗原表位,2个优势CTL抗原表位和1个优势线性B细胞抗原表位。Rv1772蛋白与含有ANTAR结构域的MTB蛋白具有高度同源性。Rv1772蛋白与Rv1592c、Rv0340、efpA、kasA、fbpC、oxyR、Rv2242、iniB、ndh、fadE24有相互作用。结论Rv1772蛋白含多个潜在的优势T细胞抗原表位和B细胞抗原表位,且能与其他蛋白相互作用,其可作为抗结核疫苗的优势抗原。

Objective To analyze the structure and function of Rv1772 protein in Mycobacterium tuberculosis(MTB).Methods Gene information for Rv1772 was obtained from the National Center for Biotechnology Information(NCBI).Bioinformatics tools were utilized to analyze the structure and function of Rv1772 protein.Results The Rv1772 protein had a relative molecular mass of 10896.28 Da and consists of 103 amino acids.It exhibited a gravy index of 77.96 and an instability coefficient of 43.98(>40),indicating it was an unstable protein.The average hydrophilicity of Rv1772 was-0.105,with a solubility index of 0.49.The protein comprised only intracellular and extracellular domains,lacked transmembrane regions,suggesting it was a non-transmembrane protein.Rv1772 lacked a signal peptide[D value=0.112(<0.45)],confirming its solubility and cytoplasmic localization.Rv1772 contained six serine phosphorylation sites and five threonine phosphorylation sites,potentially involved in regulating signal transduction during MTB infection.The secondary structure of Rv1772 consisted ofα-helix(52.43%),β-sheet(9.71%),β-turn(4.85%),and random coil(33.01%).It predominantly featuredα-helical structures,suggesting multiple B-cell antigenic epitopes.Rv1772 harbored three IFN-γ-induced HTL antigenic epitopes,two dominant CTL antigenic epitopes,and one prominent linear B-cell antigenic epitope.It exhibited high homology with MTB proteins containing the ANTAR domain.Rv1772 interacted with Rv1592c,Rv0340,efpA,kasA,fbpC,oxyR,Rv2242,iniB,ndh,and fadE24 proteins.Conclusion Rv1772 protein contains multiple potential dominant T-cell and B-cell antigenic epitopes,interacts with other proteins,and thus may serve as a promising antigen for tuberculosis vaccine development.