A novel sucrose hydrolase from the bombycoid silkworms Bombyx mori, Trilocha varians, and Samia cynthia ricini with a substrate specificity for sucrose.
A novel sucrose hydrolase from the bombycoid silkworms Bombyx mori, Trilocha varians, and Samia cynthia ricini with a substrate specificity for sucrose.
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DOI：
10.1016/j.ibmb.2015.04.005
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发表时间：
2015-06
影响因子：
3.8
通讯作者：
Huabing Wang;T. Kiuchi;S. Katsuma;T. Shimada
中科院分区：
文献类型：
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作者：
Huabing Wang;T. Kiuchi;S. Katsuma;T. Shimada
虽然膜相关蔗糖酶活性已被检测到在各种鳞翅目物种的中肠，它还没有被确定和表征在分子水平上。在本研究中，我们从三种家蚕中鉴定了一个新的蔗糖水解酶（SUH）基因，分别命名为BmSuh、TvSuh和ScSuh。EST数据表明BmSui是家蚕幼虫中肠糖苷水解酶的主要基因之一。这些基因几乎完全表达在幼虫中肠在所有三个物种，主要是在喂养阶段。SUH属于糖苷水解酶家族13，与昆虫麦芽糖酶具有显著的同源性。酶促分析表明，重组SUH是不同于传统的麦芽糖酶，并表现出底物特异性蔗糖。重组BmSUH对糖模拟生物碱的敏感性低于TvSUH和ScSUH，这可能解释了为什么桑肠杆菌中的蔗糖酶活性受桑葚来源的糖模拟生物碱的影响较小。
Although membrane-associated sucrase activity has been detected in the midgut of various lepidopteran species, it has not yet been identified and characterized at the molecular level. In the present study, we identified a novel sucrose hydrolase (SUH) gene from the following three bombycoid silkworms: Bombyx mori,Trilocha varians, andSamia cynthiariciniand named themBmSuh,TvSuh, andScSuh, respectively. The EST dataset showed thatBmSuhis one of the major glycoside hydrolase genes in the larval midgut ofB. mori. These genes were almost exclusively expressed in the larval midgut in all three species, mainly at the feeding stage. SUHs are classified into the glycoside hydrolase family 13 and show significant homology to insect maltases. Enzymatic assays revealed that recombinant SUHs were distinct from conventional maltases and exhibited substrate specificity for sucrose. The recombinant BmSUH was less sensitive to sugar-mimic alkaloids than TvSUH and ScSUH, which may explain the reason why the sucrase activity in theB. morimidgut was less affected by the sugar-mimic alkaloids derived from mulberry.