高粱外种皮原花青素四聚体对远缘链球菌6715粘附的影响

发布时间：2018-08-19 05:48

【摘要】：本文研究高粱外种皮原花青素四聚体(sorghum episperm procyanidin tetramer,SEPT)对远缘链球菌6715(S.sobrinus 6715)初始粘附及其致龋毒力因子-葡萄糖基转移酶(glucosyltransferase,GTF)的抑制效果。采用唾液包被羟基磷灰石(saliva coated hydroxylapatite,SHA)体外模型研究SEPT对S.sobrinus 6715初始粘附的影响。通过PCR扩增S.sobrinus 6715 GTF-I的催化活性区(catalytic region,CAT)的基因片段到质粒Pgex-4T-1中,转化至大肠杆菌T7 Express competent,IPTG诱导表达,纯化浓缩表达产物,获得目标蛋白GTF-I/CAT。再用不同浓度SEPT处理GTF-I/CAT,根据其水不溶性多糖产量(water insoluble glucosyltransferase,WIS)评价SEPT对GTF-I/CAT酶活力的抑制。实验结果表明,SEPT能够有效抑制S.sobrinus 6715在SHA的初始粘附,并具有一定的浓度效应关系;通过基因克隆表达获得的GTF-I/CAT蛋白酶活为8.446 m IU,产多糖能力为1.603 mg/(mg·h)。SEPT能明显抑制GTF-I/CAT产生WIS(p0.01)。说明SEPT既可以有效抑制S.sobrinus 6715的初始粘附过程,又可以通过作用GTF-I的CAT区减少WIG的合成,抑制蔗糖依赖性粘附减少S.sobrinus 6715在牙齿表面的粘附聚集,从而干预龋齿的发生。
[Abstract]:The inhibitory effect of sorghum outer seed coat (sorghum episperm procyanidin tetramerosome SEPT on the initial adhesion of Streptococcus distalis 6715 (S.sobrinus 6715) and its caries virulence factor glucosyltransferase (GTF) was studied. In vitro model of salivary coated hydroxyapatite (saliva coated hydroxylapatite was used to study the effect of SEPT on the initial adhesion of S.sobrinus 6715. The catalytic region cat gene fragment of S.sobrinus 6715 GTF-I was amplified by PCR and transformed into plasmid Pgex-4T-1, then transformed into E. coli T7 Express competence IPTG to induce expression, purified the concentrated expression product, and obtained the target protein GTF-I / CAT. GTF-I / CAT was treated with different concentrations of SEPT, and the inhibition of SEPT on the activity of GTF-I/CAT was evaluated by (water insoluble glucosyltransferase (WIS). The results showed that sept could effectively inhibit the initial adhesion of S.sobrinus 6715 to SHA and had a certain concentration effect relationship, and the activity of GTF-I/CAT protease expressed by gene cloning was 8.446 m, and the ability of producing polysaccharide was 1.603 mg/ (mg h). SEPT could significantly inhibit the production of WIS by GTF-I/CAT (p0.01). The results indicated that SEPT could effectively inhibit the initial adhesion of S.sobrinus 6715, reduce the synthesis of WIG by the CAT region of GTF-I, and inhibit sucrose dependent adhesion to reduce the adhesion and aggregation of S.sobrinus 6715 on the surface of teeth, thus interfering with the occurrence of dental caries.
【作者单位】：华中农业大学食品科学技术学院环境食品学教育部重点实验室;普健生物(武汉)科技有限公司;
【基金】：国家自然基金项目(31271939)
【分类号】：R378.12

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