生物技术进展 ›› 2012, Vol. 2 ›› Issue (2): 124-129.DOI: 10.3969/j.issn.2095-2341.2012.02.

• 研究论文 • 上一篇    下一篇

肠膜明串珠菌α-葡萄糖苷酶基因克隆表达及酶学性质

李书涛,樊攀,程景伟,杨雪鹏*   

  1. 郑州轻工业学院食品与生物工程学院, 郑州 450002
  • 收稿日期:2012-01-09 出版日期:2012-03-25 发布日期:2012-02-20
  • 通讯作者: 杨雪鹏,博士,副教授,硕士生导师,研究方向为酶分子工程及应用,食品发酵与酿造。E-mail:yangxuepeng@zzuli.edu.cn
  • 作者简介:李书涛,硕士研究生,研究方向为生物化工与生物催化(酶制剂)。E-mail:lilongfeixy888@163.com。
  • 基金资助:

    河南省重点科技攻关项目(102102110044)资助。

Cloning and Expression of an α-Glucosidase Gene from Leuconostoc mesenteroides and Biochemical Characterization of the Recombinant Enzyme

LI Shu-tao, FAN Pan, CHENG Jing-wei, YANG Xue-peng   

  1. College of Food and Biological Engineering, Zhengzhou University of Light Industy, Zhengzhou 450002, China
  • Received:2012-01-09 Online:2012-03-25 Published:2012-02-20

摘要: 肠膜明串珠菌(Leuconostoc mesentcroides ATCC 8293)基因组中存在一个编码糖苷酶家族3保守区段的基因(Leum_0289),根据该基因序列设计引物,经过扩增和重组,成功将该基因插入到表达载体pET28a(+)中,实现了该基因的诱导表达。该基因包含2 226个碱基,编码742个氨基酸,编码蛋白质理论预测分子质量为75 kDa,表达蛋白经SDS-PADE分析,分子质量与理论值基本一致。纯化后的蛋白经酶活测定,发现该酶只能水解α-对硝基苯酚葡萄糖苷(pNPG)底物,无水解甘露糖、蔗糖、纤维二糖、乳糖和龙胆二糖的活性,遂命名为α-葡萄糖苷酶。进一步酶学性质研究表明该酶的最适反应温度和最适反应pH分别为40℃和pH 6.5,Fe2+、Ca2+、Mg2+对重组α-葡萄糖苷酶有明显激活作用,而Cu2+、Zn2+对其有一定的抑制作用。

关键词: 肠膜明串珠菌, 克隆与表达, &alpha, -葡萄糖苷酶

Abstract: A putative glycosidase family 3 gene (Leum _0289) was amplified from Leuconostoc mesentcroides ATCC 8293 genomic DNA and sub-cloned into the vector pET28a(+) to obtain a recombinant plasmid pET28a-Glu. The gene is composed of 2 226 bp nucleotides which encodes 742 amino acid residues with calculated molecular mass of 75 kDa. The enzyme assay results showed that the protein can not hydrolyze maltose, sucrose, cellobiose, lactose and gentiobiose except p-nitrohenyl-α-glucopyranoside substrate. The protein was then designated α-glucosidase. The optimum temperature and pH was 40℃ and 6.5, respectively. The enzyme is activated by Fe2+, Ca2+, Mg2+, but inhibited by Cu2+ and Zn2+.

Key words: Leuconostoc mesentcroides, gene cloning and expression, α-glucosidase