Hyperexpression of two Aspergillus Niger Xylanase Genes in Escherichia Coli and Characterization of the Gene Products.
Hyperexpression of two Aspergillus Niger Xylanase Genes in Escherichia Coli and Characterization of the Gene Products.
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DOI：
10.1590/s1517-83822010000300030
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发表时间：
2010-07
期刊：
影响因子：
--
通讯作者：
Qiao D
中科院分区：
文献类型：
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作者：
Yi X;Shi Y;Xu H;Li W;Xie J;Yu R;Zhu J;Cao Y;Qiao D
通过对单个基因产物的分析，可以阐明特定酶在A.尼日尔.利用RT-PCR技术从尼日尔SCTCC 400264（SCTCC，China）中分离到两个编码共产1，4-β-D-木聚糖酶前体的基因xynA 1和xynB，并在大肠杆菌BL 21中成功表达。xynA 1和xynB基因的核苷酸序列分析表明，它们之间的同源性仅为52.5%。对重组酶的酶学性质进行了研究，结果表明：重组酶XYNA 1的比活力为16.58 U/mg，重组酶XYNB的比活力为1201.7 U/mg，重组酶XYNA 1的最适温度和pH分别为35 °C和3.0，而重组酶XYNB的最适温度和pH分别为55 °C和5.0;重组XYNB显示出比重组XYNA 1高得多的热稳定性;与重组XYNA 1没有活性相比，重组XYNB在60 °C下在水中孵育60分钟后显示出94%的最大活性。不同的金属离子对两种重组木聚糖酶的活性有不同的影响。
The analysis of individual gene product should enable to clarify the role of a particular enzyme in a complex xylanase system of A. niger. The two genes encoding precursors of co-produced endo-1,4-β-D-xylanases, xynA1 and xynB, were isolated from Aspergillus niger SCTCC 400264 (SCTCC, China) by using RT-PCR technique and then successfully expressed in Escherichia coli BL21. The nucleotide sequences of the xynA1 and xynB genes revealed that they were only 52.5% homology to each other. Characterization of the recombinant enzymes revealed the different properties: the specific activity of recombinant XYNA1 was 16.58 U/mg compared to 1201.7 U/mg for recombinant XYNB; The optimum temperature and pH of the recombinant XYNA1 were 35 °C and 3.0, respectively, whereas the corresponding values for the recombinant XYNB were 55 °C and 5.0, respectively; The recombinant XYNB showed much more thermostability than recombinant XYNA1; The recombinant XYNB showed 94% of maximal activity after incubating in water for 60 min at 60 °C compared to no activity for recombinant XYNA1. Various metal ions had different effects on activity between the two recombinant xylanases.