变形链球菌UA159上葡聚糖结合蛋白C的定位探讨  

Location of GbpC protein in Streptococcus mutans UA159

作　　者：胡萍[1] 边专[1] 樊明文[1] 聂敏[1] 

机构地区：[1]武汉大学口腔医学院口腔生物医学工程教育部重点实验室,430079

出　　处：《中华口腔医学杂志》2007年第6期349-352,共4页Chinese Journal of Stomatology

基　　金：国家自然科学基金(30670115)

摘　　要：目的探索 C 端结构变异为亮氨酸-脯氨酸-任意氨基酸-丙氨酸-甘氨酸(LPXAG)的葡聚糖结合蛋白 C(glucan binding protein C,GbpC)是否在变形链球菌 UA159的细胞壁上。方法用PCR 法扩增变形链球菌 UA159 GbpC C 端的编码基因片段,推测和分析 C 端氨基酸序列组成;分别提取上清蛋白、胞内蛋白和胞壁蛋白,用 Western blot 法在变形链球菌 UA159各成分中检测 GbpC;用免疫金标直接观察 GbpC 的表达位置;应激条件下进行多聚糖依赖黏附实验。结果变形链球菌 UA159GbpC C 端亮氨酸-脯氨酸-任意氨基酸-苏氨酸-甘氨酸(LPXTG)的结构变异为 LPXAG;免疫印迹可以在细菌的壁蛋白中检测到 GbpC;电镜下可以观察到金颗粒围绕细菌细胞壁聚集;变形链球菌 UA159在应激条件下表现为多糖依赖黏附实验阳性。结论 C 端为 LPXAG 的 GbpC 仍然锚定在细菌的细胞壁上。Objective To determine whether the glucan binding protein C （GbpC） with LPXAG motif is anchoring to the cell wall of the Streptococcus mutans UA159 （S. mutans UA159 ）. Methods S. mutans UA159 GbpC C terminal gene segment was amplified by PCR , the gene sequences and the deduced amino acid sequences were analyzed. In order to locate the GbpC of S. mutans, the study isolated the wall fraction following digestion of the cell wall by N-acetylmuramidase, and the GbpC was detected by Western blot analysis. GbpC S. mutans UA159 was located with gold particles. Furthermore, the dextrandependent aggregation （ddag） phenotype of the S. mutans UA159 under stress condition was observed. Results S. mutans UA159 GbpC C-terminal LPXTG motif was replaced by LPXAG motif. GbpC was observed in the cell wall component and immunogold experiment showed that the gold particles distributed around the cell wall surface. S. mutans UA159 exhibited ddag ＋. Conclusions GbpC with LPXAG motif was still anchoring to the cell wall.

关 键 词：链球菌 变异 免疫组织化学 葡聚糖结合蛋白C 

分 类 号：R780.2[医药卫生—口腔医学]