D-阿洛酮糖作为一种新型低热量功能性甜味剂,可以通过D-塔格糖-3-差向异构酶家族,以D-果糖为底物C-3位异构化得到。一个新的来源于微生物Clostridium scindens ATCC 35704中ZP 0243228的D-塔格糖-3-差向异构酶基因(CS-DTE),通过克隆并成功导入E.coli BL21(DE3)中,构建了基因重组菌,诱导目的重组基因过量表达;经亲和层析纯化的重组蛋白样品进行SDS-PAGE分析,在约31 ku处出现显著的特征蛋白条带;通过对其活性检测表明,该重组酶分别以D-塔格糖和D-果糖为底物,可以生成D-山梨糖和D-阿洛酮糖,转化率分别为8.6%和27.9%。

D-tagatose-3-epimerase(DTE) catalyzes the epimerization of various ketohexoses at C-3 position,and commonly catalyzes the reversible interconversion of D-fructose to D-psicose,which is a novel useful low-calorie sweetener with many beneficial effects.A new gene,encoding the hypothetical protein with locus ZP 02432283 from the Clostridium scindens ATCC 35704 was cloned and over-expressed in E.coli.BL21(DE3).The recombinant protein was purified to electrophoretical homogeneity by affinity chromatography using Chelating Sepharose Fast Flow resin and analyzed by SDS-PAGE,showing approximately 31 ku characteristic protein.The recombinant enzyme activity was determined by measuring D-sorbose formed using D-tagatose and D-psicose formed using D-fructose as a substrate,the bioconversion rate reached 8.6% and 27.9%,respectively.