Heterologous expression and biochemical characterization of a thermostable xylulose kinase from Bacillus coagulans IPE22.
Heterologous expression and biochemical characterization of a thermostable xylulose kinase from Bacillus coagulans IPE22.
复制标题
凝结芽孢杆菌 IPE22 热稳定性木酮糖激酶的异源表达和生化特征。
DOI：
10.1002/jobm.201800482
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发表时间：
2019
影响因子：
3.1
通讯作者：
Liu Fengsong
中科院分区：
文献类型：
--
作者：
Zhang Yuming;Zhao Chunhai;Ni Zhihua;Shao Menghua;Han Mengying;Huang Dawei;Liu Fengsong
木纤维素酶是木糖代谢过程中的一种重要酶，被认为是木质纤维素戊糖可持续利用的重要生物催化剂。凝结芽孢杆菌IPE22具有较强的高温发酵木糖的能力，是炼油厂理想的细菌。然而，b.凝聚木糖的利用机制尚不清楚，相关的有前途的酶还有待开发。在本研究中，从B。凝固素IPE22(BC-XK)在大肠杆菌BL21(DE3)中表达，其开放阅读框长度为1536 ，编码511个氨基酸的蛋白质(56.15 kDa)。对BC-XK和其他细菌的同源物进行了多序列比对，并构建了系统发育树，以评估BC-XK和其他细菌同源物之间的差异。BC-XK对高温具有广泛的适应性，在pH 8.0、60 °C时表现出最好的酶活性，被镁、锰、钴离子激活。同时，该酶在60 °C下保持活性至少180 min，对木糖和三磷酸腺苷的BC-XK值分别为1.29 mm和0.76 mm。BC-XK的高温稳定性表明它是一种有吸引力的工业应用候选者。
Xylulose kinase is an important enzyme involved in xylose metabolism, which is considered as essential biocatalyst for sustainable lignocellulosic‐derived pentose utilization.Bacillus coagulansIPE22 is an ideal bacterium for refinery due to its strong ability to ferment xylose at high temperature. However, theB. coagulansxylose utilization mechanism remains unclear and the related promising enzymes need to be developed. In the present study, the gene coding for xylulose kinase fromB. coagulansIPE22 (Bc‐XK) was expressed inEscherichia coliBL21 (DE3).Bc‐XKhas a 1536 bp open reading frame, encoding a protein of 511 amino acids (56.15 kDa). Multiple sequence alignments were performed and a phylogenetic tree was built to evaluate differences among Bc‐XK and other bacteria homologs. Bc‐XK showed a broad adaptability to high temperature and the enzyme displayed its best performance at pH 8.0 and 60 °C. Bc‐XK was activated by Mg2+, Mn2+, and Co2+. Meanwhile, the enzyme could keep activity at 60 °C for at least 180 min.KMvalues of Bc‐XK for xylulose and ATP were 1.29 mM and 0.76 mM, respectively. The high temperature stability of Bc‐XK implied that it was an attractive candidate for industrial application.