黄色瘤胃球菌木聚糖酶基因xynB的异源表达与酶学性质研究  

Heterologous Expression and Enzymatic Properties of Xylanase Gene xynB Derived from Ruminococcus flavefaciens

作　　者：毕海红 胡馨元 王玉洁 翟圣君 张竞月 孙丽萍 王琴 夏呈强 BI Haihong;HU Xinyuan;WANG Yujie;ZHAI Shengjun;ZHANG Jingyue;SUN Liping;WANG Qin;XIA Chengqiang(College of Animal Science,Shanxi Agricultural University,Taigu Shanxi 030801,China)

机构地区：[1]山西农业大学动物科学学院,山西太谷030801

出　　处：《现代畜牧科技》2024年第2期1-5,共5页Modern Animal Husbandry Science & Technology

基　　金：国家自然科学基金青年项目(32002143);国家重点研发计划专项子课题(2022YFD1300705);山西省重点研发计划项目(202102140601019);山西省优秀博士来晋工作奖励项目(SXYBKY2019024)。

摘　　要：该试验以黄色瘤胃球菌基因组为模板,通过PCR扩增获得目的基因xynB,将xynB与表达载体PET28a连接,获得重组载体PET28a-xynB。用IPTG对含有重组载体的大肠杆菌BL21(DE3)进行诱导表达,镍离子层析柱纯化后检测其酶学性质。生物信息学分析表明,XynB理论大小为47 kDa,预测等电点为4.49,不含信号肽,含有1个糖苷水解酶11家族结构域和1个碳水化合物结合结构域。酶学性质研究结果表明,该酶的最适pH值为5.0,最适反应温度为40℃,金属离子Mg^(2+)、Na^(+)、K^(+)和Ba^(2+)对木聚糖酶XynB有较好的激活效果。综上可知,黄色瘤胃球菌木聚糖酶XynB属于GH11家族,最适pH值为5.0,最适温度为40℃,酶比活力为62.94 U/mg。In this experiment,the genome of R.flavefaciens was used as a template,and the target gene xynB was amplified by PCR,and the recombinant vector PET28a-xynB was obtained by ligating xynB with the expression vector PET28a.The expression of Escherichia coli BL21(DE3)containing recombinant vector was induced by IPTG,and its enzymatic properties were detected after purification by nickel ion chromatogram.After bioinformatics analysis,it was found that the theoretical size of XynB was 47 kDa,the predicted isoelectric point was 4.49,there was no signal peptide,it contained a glycoside hydrolase 11 family domain and a carbohydrate binding domain.The results of enzymatic properties showed that the optimal pH of the enzyme was 5.0.The optimal reaction temperature was 40℃.The metal ions Mg^(2+),Na^(+),K^(+) and Ba^(2+) had a good activation effect on XynB.In conclusion,R.flavefaciens xylanase XynB belonged to the GH11 family,with an optimal pH of 5.0,an optimal temperature of 40℃,and an enzyme specific activity of 62.94 U/mg.

关 键 词：黄色瘤胃球菌 木聚糖酶 XYNB 异源表达 酶学性质 

分 类 号：S816.3[农业科学—饲料科学]