甜茶甙对变形链球菌葡糖基转移酶的影响

目的研究甜茶甙对变形链球菌葡糖基转移酶的影响。方法实验组采用二倍稀释法,用胰蛋白胨-胰蛋白月示-酵母提取物液体培养基（tryptone-tryptose-yeast extract medium,TTY）将甜茶甙配制成50.00g/L、25.00g/L、12.50g/L、6.25g/L、3.13g/L的溶液。对照组采用不含甜茶甙的TTY培养基。各组分别加入变形链球菌液,厌氧培养24h后离心、盐析得胞外葡糖基转移酶的粗酶,采用考马斯亮蓝法和Somogyi法分别测定总蛋白和还原糖含量,计算酶活力和比活力。结果50.00g/L、25.00g/L、12.50g/L、6.25g/L、3.13g/L甜茶甙溶液和对照组的酶活力分别为0.4775、1.1271、1.4193、6.6998、12.3490、13.9679mU。酶活力和比活力在各浓度组间差异均有统计学意义（P〈0.05）;除3.13g/L浓度组外,甜茶甙各浓度组与对照组酶活力、比活力、总蛋白含量之间差异均有统计学意义（P〈0.05）。结论甜茶甙对变形链球菌葡糖基转移酶有明显抑制作用。

Effect of Rubrus Suarissimus S.Lee Saponin on Glucosyltransferase of Streptococcus mutans

Objective To assess the effect of Rubrus Suarissimus S.Lee saponin on glucosyltransferase of Streptococcus mutans.Methods Rubrus Suarissimus S.Lee saponin was divided into 5 treatment groups by different concentrations,and 3 mL Rubrus Suarissimus S.Lee saponin and 0.3 mL Streptococcus mutans were added into each group,while 0.3 mL Streptococcus mutans and 3 mL TTY culture were added into the negative control.After 24 hours’anaerobical culturing,the suspensions were centrifuged and the glucosyltransferase were extracted.Bradford method and Somogyi method were used respectively to measure the content of total protein and enzyme activity,and the specific activity was calculated.Results The glucosyltransferase of Streptococcus mutans decreased gradually with the increase of concentration of Rubrus Suarissimus S.Lee saponin.Except for the group of 3.13 g/L,there were highly significant differences among total sample groups,and between glucosyltransferase activity or specific activity of each experimental group and control group as well （P0.05）.Conclusion Rubrus Suarissimus S.Lee saponin inhibted the glucosyltransferase of Streptococcus mutans.