催化学报

催化学报 ›› 2009, Vol. 30 ›› Issue (7): 673-678.

• 研究论文 • 上一篇    下一篇

化学修饰法表征 Bacillus smithii T7 产耐热菊粉酶催化活性中心的必需氨基酸残基

刘彬, 王静云, 包永明, 张帆, 安利佳   

  1. 大连理工大学环境与生命学院生物科学与工程系, 辽宁大连 116024
  • 收稿日期:2009-07-25 出版日期:2009-07-25 发布日期:2013-04-24

Characterization of Key Amino Acid Residues in Active Sites of Inulinase from Bacillus smithii T7 by Chemical Modification

LIU Bin, WANG Jingyun*, BAO Yongming, ZHANG Fan, AN Lijia   

  1. Department of Bioscience and Biotechnology, School of Environmental and Biological Science and Technology, Dalian University of Tech-nology, Dalian 116024, Liaoning, China
  • Received:2009-07-25 Online:2009-07-25 Published:2013-04-24

PDF

1175

被引次数

10

摘要： 采用化学修饰法研究了史氏芽胞杆菌 Bacillus smithii T7 产耐热菊粉酶活性中心氨基酸残基, 发现该酶活性中心存在一个组氨酸残基和一个谷氨酸 (或天冬氨酸) 残基. 修饰前后的酶动力学参数变化表明组氨酸残基参与了底物的结合和催化过程, 而谷氨酸 (或天冬氨酸) 的羧基亲核攻击促使底物分解. 邹氏作图法证明酶活性中心存在两个必需的色氨酸残基, 荧光和圆二色光谱研究表明色氨酸残基在酶的催化和酶的耐热性方面起重要作用.

关键词: 菊粉酶, 化学修饰, 活性中心, 氨基酸残基, 催化

Abstract: Chemical modification demonstrated that one histidine and one carboxylate residues in the active site of endo-inulinase from Bacillus smithii T7 play a key role in the catalytic function. Two tryptophan residues are necessary for the enzyme activity and are also important for the enzyme’s thermal stability.

Key words: inulinase, chemical modification, active site, amino acid residue, catalysis