建立一种能够精密检测产物右旋糖酐分子质量变化及定量跟踪检测蔗糖、葡萄糖及果糖浓度的方法.通过对比高效凝胶过滤色谱单柱和双柱串联对右旋糖酐标准品及催化产物的检测效果,探寻得到右旋糖酐分子质量检测的有效方法.同时,通过构建右旋糖酐蔗糖酶耦合两级膜探索得到右旋糖酐的合成机理是葡萄糖基在右旋糖酐蔗糖酶活性位点上,不断聚合,直至达到一定的分子质量( mw＞106Da)才脱落,而不是一个从小到大、慢慢聚合、不断脱落的过程.%A precise method for the determination of changes in the molecular mass of dextran and the quantification of sucrose, fructose and glucose concentration during the dextransucrase-catalyzed reaction of sucrose was presented in this paper. High performance gel filtration chromatography (HPGFC) with one column and with two tandem columns were compared for their efficiencies in the determination of dextran standard and the catalytic reaction products in order to develop a robust method to measure the molecular mass of dextran. By dextransucrase combined with two-stage membrane treatment, we investigated the mechanism underlying dextran synthesis. It was found that the synthesis process was continuous aggregation of glucosyl group at the active site of dextransucrase until reaching a specific molecular mass (> 106Da) before detachment rather than stepwise aggregation and then detachment.
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