MECHANISM OF POLYSACCHARIDE PRODUCTION FROM SUCROSE .3. DONOR-ACCEPTOR SPECIFICITY OF LEVANSUCRASE FROM AEROBACTER-LEVANICUM
MECHANISM OF POLYSACCHARIDE PRODUCTION FROM SUCROSE .3. DONOR-ACCEPTOR SPECIFICITY OF LEVANSUCRASE FROM AEROBACTER-LEVANICUM
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DOI：
10.1042/bj0640340
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发表时间：
1956-01-01
影响因子：
4.1
通讯作者：
AVIGAD, G
中科院分区：
文献类型：
--
作者：
HESTRIN, S;FEINGOLD, DS;AVIGAD, G
本文介绍了一种改进的左旋链霉菌左旋糖苷酶的提取工艺和微量测定左旋糖苷酶活性的方法。以蔗糖为原料，经无细胞左旋蔗糖酶溶液甲基化制备Levan。用纸层析法对甲基化多糖的水解产物进行检测表明，它具有与来自左旋藻和其他细菌培养物的Levan相似的分枝结构。红外光谱分析进一步支持了这一结论。考察了左旋蔗糖酶对几类低聚果糖糖苷代表的影响。所有具有末端[β]-呋喃果糖苷基团与醛糖的异规碳相连的化合物都形成Levan，而具有相同基团与甲醇碳相连的化合物不会被左旋蔗糖酶攻击。说明前者以蔗糖为代表的果糖键具有较高的自由能含量。因此，这一类的成员由高能符号fr[图像]R来描述，而第二类的化合物则被指定为fr
An improved procedure for extraction of A. levanicum levansucrase and a micro test for levansucrase activity are described. Levan produced from sucrose by cell-free levansucrase solution was methylated. Examination by paper chromatography of the products of hydrolysis of the methylated polysaccharide indicate that it has a branched structure similar to that of levan from cultures of A. levanicum and other bacterial species. This conclusion was further supported by infrared analysis. The effect of levansucrase on representatives of several classes of oligofructosides was examined. All compounds examined with a terminal [beta]-fructofuranosidic group linked to the anomeric carbon of an aldose formed levan, whereas compounds with the same group linked to a carbinol carbon were not attacked by levansucrase. It is suggested that the fructosidic linkage in the former group, typified by sucrose, has the higher free-energy, content. Members of this class are therefore described by a high-energy symbol fr[image]R, whereas compounds of the second class are designated fr