Enzymatic and regulatory properties of the trehalose-6-phosphate synthase from the thermoacidophilic archaeon Thermoplasma acidophilum
Enzymatic and regulatory properties of the trehalose-6-phosphate synthase from the thermoacidophilic archaeon Thermoplasma acidophilum
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嗜热嗜酸古菌嗜酸热原体的海藻糖 6-磷酸合酶的酶学和调节特性
DOI：
10.1016/j.biochi.2014.01.018
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发表时间：
2014-06-01
期刊：
影响因子：
3.9
通讯作者：
Liu, Bo
中科院分区：
文献类型：
--
作者：
Gao, Yanyan;Jiang, Ying;Liu, Bo
海藻糖-6-磷酸合成酶在海藻糖代谢中起重要作用。催化葡萄糖从UDP-葡萄糖（UDPG）转化为葡萄糖6-磷酸，生成海藻糖-6-磷酸。在这里，我们描述了一个海藻糖-6-磷酸合酶的嗜热嗜酸古菌嗜酸热浆菌的表征。该二聚体酶可利用UDPG、ADP-葡萄糖（ADPG）和GDP-葡萄糖（GDPG）作为糖基供体，利用各种磷酸化单糖作为糖基受体。该酶的最适反应温度为60 ℃，最适pH为6，具有较好的pH稳定性和热稳定性。二价金属离子和聚阴离子肝素和硫酸软骨素对酶活性有促进作用。此外，该蛋白对添加剂乙醇、EDTA、尿素、DTT、SDS、β-巯基乙醇、甲醇、异丙醇和正丁醇具有相当大的抗性。分子模拟和突变分析表明，N-环区域是重要的催化效率的酶，表明不同的海藻糖-6-磷酸脱氢酶的N-环序列中的不同作用。(C)2014年Elsevier Masson SAS。All rights reserved.
Trehalose-6-phosphate synthase plays an important role in trehalose metabolism. It catalyzes the transfer of glucose from UDP-glucose (UDPG) to glucose 6-phosphate to produce trehalose-6-phosphate. Herein we describe the characterization of a trehalose-6-phosphate synthase from the thermoacidophilic archaeon Thermoplasma acidophilum. The dimeric enzyme could utilize UDPG, ADP-Glucose (ADPG) and GDP-Glucose (GDPG) as glycosyl donors and various phosphorylated monosaccharides as glycosyl acceptors. The optimal temperature and pH were found to be 60 C and pH 6, and the enzyme exhibited notable pH and thermal stability. The enzymatic activity could be stimulated by divalent metal ions and polyanions heparin and chondroitin sulfate. Moreover, the protein was considerably resistant to additives ethanol, EDTA, urea, DTT, SDS, beta-mercaptoethanol, methanol, isopropanol and n-butanol. Molecular modeling and mutagenesis analysis revealed that the N-loop region was important for the catalytic efficiency of the enzyme, indicating different roles of N-loop sequences in different trehalose-6-phosphate synthases. (C) 2014 Elsevier Masson SAS. All rights reserved.