幽门螺杆菌TNF-α诱导蛋白的生物信息学分析

Bioinformatics analysis on TNF-αinducing protein of Helicobacter. pylori

肿瘤坏死因子诱导蛋白Tipα是幽门螺杆菌特有的一个膜相关蛋白。它可以激活核因子κB,并诱导多种细胞因子和趋化因子的表达,导致胃炎和随后的肿瘤发生。它是幽门螺杆菌和胃癌发生之间的关键分子。本文利用生物信息学工具分析Tipα序列,预测其信号肽、跨膜区、疏水性、二级结构、三级结构等性质。结果:Tipα具有一段信号肽、脂蛋白信号肽酶切位点及脂盒模体。另外该蛋白没有跨膜区,可能是一个外周膜蛋白。Tipα的三级结构说明,该蛋白形成了一个致密的球状结构,Tipα的二级结构以α螺旋为主。

Tumor necrosis factor-α （TNF-α） inducing protein （Tipct） is a membrane-associated protein of It. pylori, unique for this bacterium. Tipα can activate nuclear faetor-κB （NF-κB） and induce expression of some chemokine genes and cytokine genes, resulting in inflammation in mieroenvironment of the stomach and subsequent cancer development. This protein is a key molecule linking H. pylori with stomach cancer development. In this paper, the amino acid sequence of Tipα was analyzed and predicted by the tools of bioinformatics in the following aspects：signal peptides, transmembrane topological structures, hydrophobicity or hydrophilicity, secondary and tertiary structure of protein. The results showed that Tipα included a 24-aa signal peptide, and contained a cleavage site for lipoprotein signal peptide and a lipbox motif. The protein had no transmembrane domain, and may be a peripheral membrane protein. The predicted secondary structure of Tipoα contained mostly α-helical conformation. The three-dimensional model of Tipct indicated that the protein folded as a compact and globular domain, and might be soluble.