血链素的提纯和初步鉴定

目的　提纯血链素 ,为进一步从分子水平研究血链球菌及血链素对牙周可疑致病菌的作用机理提供实验基础。方法　利用 DEAE- Sepharose梯度洗脱和葡聚糖凝胶过滤相结合的方法 ,将 4 72 g/L 硫酸铵沉淀的血链素粗提物进一步提纯 ,测定其抑菌活性 ,并进行初步鉴定。结果　提纯获得了纯化的血链素 ,初步鉴定显示其具有蛋白质的性质 ,SDS- PAGE电泳结果显示主要区带一条 ,相对分子质量为 6 5× 1 0 3。体外抑菌试验显示提纯物对牙龈卟啉单胞菌、中间普雷沃菌和具核梭杆菌具有较强抑菌能力。结论　纯化血链素具有拮抗牙周可疑致病菌的重要作用 ,在牙周微生态防治方面具有良好的应用前景

Purification and Characterization of Sanguicin--a Bacteriocin Produced by Streptococcus Sanguis

OBJECTIVE: Streptococcus sanguis plays an important Role in maintaining the periodontal microecological balance. Previous studies have demonstrated that sanguicin--a kind of bacteriocin produced by S. sanguis has a prominent function of inhibiting the growth of putative periodontopathic bacteria (PPB). The aim of this study was to purify sanguicin and investigate its characters. METHODS: The raw extract of sanguicin was obtained from cells of S. sanguis by ultrasonication, salting out and dialysis. Then the diethyl-aminoethyl-sepharose gradual washing was done in conjunction with glucosan gel filtration for in the purfication of sanguicin. The characters of purified sanguicin were determined and its inhibitiory effect on PPB was measured by agar diffusion test. RESULTS: The purifed sanguicin was obtained; it was heat labile and proteinaceous; and by SDS-PAGE, it showed a main band with the relative molecular mass of 65 x 10(3). The purifed sanguicin had a strong inhibitory effect on P. gingivalis, P. intermedia and F. nucleatum in vitro. CONCLUSION: Our methods are useful for the purification of sanguicin. Sanguicin has inhibitory effect on PPB obviously and will have a good prospect in periodontal ecological therapy.