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›› 2012, Vol. 12 ›› Issue (2): 283-287.

• 生化工程专栏 • 上一篇    下一篇

以L-谷氨酰胺-锌(II)配合物为供体酶法制备茶氨酸及其反应机理

胡国梅 姚忠 王浩琦 周治 熊强 徐虹 韦萍   

  1. 南京工业大学食品与轻工学院 南京工业大学食品与轻工学院 南京工业大学食品与轻工学院 南京工业大学制药与生命科学学院 南京工业大学食品与轻工学院 南京工业大学食品与轻工学院 南京工业大学制药与生命科学学院
  • 收稿日期:2011-12-22 修回日期:2012-04-10 出版日期:2012-04-20 发布日期:2012-04-20
  • 通讯作者: 姚忠

Investigation on Enzymatic Synthesis of L-Theanine with Zinc(II)-L-Glutamine Complex and Its Mechanism

HU Guo-mei， YAO Zhong WANG Hao-qi， ZHOU Zhi XIONG Qiang XU Hong WEI Ping   

  1. College of Food Science and Light Industry,Nanjing University of Technology College of Food Science and Light Industry,Nanjing University of Technology College of Food Science and Light Industry,Nanjing University of Technology College of Life Science and Pharmacy, Nanjing University of Technology College of Life Science and Pharmacy, Nanjing University of Technology College of Food Science and Light Industry,Nanjing University of Technology College of Life Science and Pharmacy, Nanjing University of Technolog
  • Received:2011-12-22 Revised:2012-04-10 Online:2012-04-20 Published:2012-04-20
  • Contact: YAO Zhong

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摘要： 针对酶法合成茶氨酸中存在的自转肽副反应，合成了L-谷氨酰胺-锌(II)配合物Zn(Gln)2，以其为供体、乙胺为受体、枯草芽孢杆菌B. subtilis GGT为催化剂，酶法制备茶氨酸. 结果表明，Zn(Gln)2在反应主体相稳定性良好，以Zn(Gln)2为供体可有效抑制自转肽副反应；B. subtilis GGT对Zn(Gln)2和Gln的亲和力常数分别为0.53 mmol/L和1.01 mmol/L. 在Zn(Gln)2 6.0 mmol/L、乙胺200 mmol/L及GGT 0.5 U/mL条件下，经37℃反应2 h，茶氨酸浓度最高可达7.38 mmol/L，较以Gln为供体时提高了14.42%.

关键词: L-茶氨酸, L-谷氨酰胺-锌(II)配合物, 酶法合成, 自转肽

Abstract: To restrain the side reaction of autotranspeptidation, the complex of L-glutamine-Zn(II) [Zn(Gln)2] was prepared and used for enzymatic synthesis of theanine via g-glutamyltranspeptidation (GGT) reaction. The stability and reactivity of Zn(Gln)2 were satisfactory under the reaction conditions. Moreover, autotranspeptidation was restrained effectively when Zn(Gln)2 instead of L-glutamine (Gln) was used as the g-glutamyl donor. The kinetic parameter Km of B. subtillus GGT toward Zn(Gln)2 and Gln was calculated to be 0.53 and 1.01 mmol/L respectively. Under the conditions of 6 mmol/L Zn(Gln)2, 200 mmol/L ethylamine, and 0.5 U/mL GGT, 7.38 mmol/L of theanine was obtained after incubation at 37℃ for 2 h, indicating an increase of 14.42% compared with that using Gln as the donor substrate.

Key words: L-theanine, g-glutamyltranspeptidase, enzymatic synthesis, autotranspeptidation