Improvement of GH10 family xylanase thermostability by introducing of an extra α-helix at the C-terminal
Improvement of GH10 family xylanase thermostability by introducing of an extra α-helix at the C-terminal
复制标题
通过在 C 端引入额外的 α 螺旋提高 GH10 家族木聚糖酶的热稳定性
DOI：
10.1016/j.bbrc.2019.05.163
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发表时间：
2019-07-30
影响因子：
3.1
通讯作者：
Zhang, Ruifu
中科院分区：
文献类型：
--
作者：
Li, Guangqi;Chen, Xiaojuan;Zhang, Ruifu
木聚糖酶是一种重要的工业应用酶，通常要求酶在高温条件下保持活性。本研究对高温堆肥真菌烟曲霉Z5产生的GH 10家族木聚糖酶XynAFO的热稳定机制进行了研究。XynAFO表现出优异的热稳定性，在70 ℃孵育1 h后仍能保持50%的相对活性。构建了XynAFO的同源模拟结构，并在催化结构域和碳水化合物结合模块结构域之间的接头区域中发现了由聚苏氨酸组成的α-螺旋。分子动力学模拟和生化实验均证明了α-螺旋对XynAFO的热稳定性起着重要作用。将该多聚苏氨酸区域引入另一种GH 10家族木聚糖酶的C-末端改善了其热稳定性。研究结果表明，在GH 10家族木聚糖酶催化结构域C端的多聚苏氨酸α-螺旋对提高其耐热性具有重要作用，为木聚糖酶的热稳定性改造提供了新的策略。(C)2019爱思唯尔公司All rights reserved.
Xylanase is an important enzyme in industrial applications, which usually require the enzyme to maintain activity in high-temperature condition. In this study, a GH10 family xylanase XynAFO from a thermophilic composting fungus, Aspergillus fumigatus Z5, was investigated to determine its thermostable mechanism. XynAFO showed excellent thermostability, which could maintain 50% relative activity after incubation for 1 h at 70 degrees C. The homologous modeling structure of XynAFO was constructed and an alpha-helix composed of poly-threonine has been found in the linker region between the catalytic domain and the carbohydrate-binding module domain. Both the molecular dynamics simulation and the biochemical experiments proved that the alpha-helix plays an important role in the thermostability of XynAFO. Introducing of this poly-threonine region to the C-terminus of another GH10 family xylanase improved its thermostability. Our results indicated that the poly-threonine alpha-helix at the C-terminus of the catalytic domain was important for improving the thermophilic of GH10 family xylanases, which provides a new strategy for the thermostability modification of xylanases. (C) 2019 Elsevier Inc. All rights reserved.