截短的BabA蛋白结合区(C51)具有促进幽门螺杆菌AGS细胞黏附作用

Truncated BabA binding domain(C51)promotes the binding of Helicobacter pylori to AGS cells

目的获得能与Lewis b结合的截短的BabA结合域,并评价其对幽门螺杆菌黏附人胃腺癌上皮细胞系(AGS细胞)的影响。方法采用Swiss Model分析蛋白截短后的结构变化,克隆表达截短的BabA结合区蛋白,命名为C51,用Native-PAGE蛋白电泳法检测其是否为多聚体。用流式细胞术检测C51蛋白对J99和M523两株幽门螺杆菌黏附AGS细胞的影响,并用革兰染色观察C51蛋白对幽门螺杆菌聚集的影响。结果体外表达的C51蛋白以多聚体形式存在,该蛋白促进了J99和M523的聚集并使其与AGS的黏附分别增加了12%(t=8.211,P=0.001)和22%(t=4.402,P=0.012)。结论C51蛋白仍保持了与黏附相关的空间结构,并促进了幽门螺杆菌和AGS细胞的结合。

Objective To obtain a truncated binding domain of BabA capable of binding to Lewis b and to evaluate its effect on adhesion of H.pylori to AGS cells.Methods The binding domain of BabA was truncated and the Swiss model was used to analyze structural changes.The truncated binding domain,named C51,was expressed and identified by Western blot.Native-PAGE electrophoresis was used to identify whether it is a multimer.Flow cytometry was used to detect its effect on adhesion of H.pylori J99 and M523 to AGS cells.The effect of C51 protein on H.pylori aggregation was observed by Gram staining.Results The protein C51 was expressed and purified as a multimer.It increased the aggregation of J99 and M523 strains and their binding to AGS by 12%(t=8.211,P=0.001)and 22%(t=4.402,P=0.012),respectively.Conclusion The protein C51 maintained the spatial structure related to adhesion and promoted the adhesion of H.pylori to AGS cells.