An enzyme from Streptococcus mutans forms branches on dextran in the absence of sucrose.
An enzyme from Streptococcus mutans forms branches on dextran in the absence of sucrose.
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DOI：
10.1016/0006-291x(83)91002-1
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发表时间：
1983-08
影响因子：
3.1
通讯作者：
M. M. Mccabe-M.;R. Hamelik
中科院分区：
文献类型：
--
作者：
M. M. Mccabe-M.;R. Hamelik
变形链球菌的糖基转移酶制剂中的一种酶催化了[14c]葡萄糖苷从纯化的异麦芽糖转移到没有蔗糖的受体葡聚糖，每个异麦芽糖在其非还原端含有[14c]葡萄糖苷。所得到的[14c]右旋糖酐中有一半的放射性可以抵抗淀粉- 1,6 -葡萄糖苷酶的水解。用内切葡聚糖酶处理[14c]葡聚糖导致了广泛的水解，并产生了含有分支位点的[14c]标记的极限低聚糖。[14c]标记的极限低聚糖的乙酰解产生[14c]黑糖，从而表明在没有蔗糖的情况下葡聚糖上形成分支位点。催化该反应的酶尚未确定，但似乎独立于变形链球菌的主要细胞外葡萄糖转移酶。
An enzyme in glucosyltransferase preparations from Streptococcus mutans catalyzed the transfer of [14 C] glucopyranoside from purified isomaltosaccharides, each containing [14 C] glucopyranoside at its non-reducing terminus, to acceptor dextran, in the absence of sucrose. Half of the radioactivity present in the resulting [14 C] dextrans was resistant to hydrolysis by amylo-1, 6-glucosidase. Treatment of the [14 C] dextrans with endodextranase resulted in extensive hydrolysis and produced [14 C]-labeled limit oligosaccharides containing branch sites. Acetolysis of the [14 C]-labeled limit oligosaccharides yielded [14 C] nigerose, thus indicating the formation of branch sites on dextran in the absence of sucrose. The enzyme catalyzing this reaction has not been identified but appears to be independent of the major extracellular glucosyltransferases of S. mutans.