应用化学 ›› 2021, Vol. 38 ›› Issue (6): 704-712.DOI: 10.19894/j.issn.1000-0518.200271

• 研究论文 • 上一篇    下一篇

甲酸脱氢酶催化活性的定向进化及其高效表达

张振华1, 解玉丽1, 王铁军1, 赵虹2, 唐存多1*, 阚云超1, 姚伦广1   

  1. 1南阳师范学院昆虫生物反应器河南省工程实验室,河南省南水北调中线水源区生态安全重点实验室,南阳 473061
    2河南蓝图制药有限公司,南阳 473061
  • 收稿日期:2020-09-04 修回日期:2020-12-31 出版日期:2021-06-01 发布日期:2021-08-01
  • 通讯作者: *E-mail:tcd530@126.com
  • 基金资助:
    国家自然科学基金(Nos.31900916,31870917)、河南省高校科技创新人才项目(No.21HASTIT041)和河南省高校科技创新团队(No.20IRTSTHN024)资助

Directed Evolution for Catalytic Activity of Formate Dehydrogenase and Its Overexpression

ZHANG Zhen-Hua1, XIE Yu-Li1, WANG Tie-Jun1, ZHAO Hong2, TANG Cun-Duo1*, KAN Yun-Chao1, YAO Lun-Guang1   

  1. 1Henan Provincial Engineering Laboratory of Insect Bio-reactor and Henan Key Laboratory of Ecological Security for Water Source Region of Mid-line of South-to-North, Nanyang Normal University, Nanyang 473061, China
    2Henan Life Pharmaceutical Co. LTD, Nanyang 473061, China
  • Received:2020-09-04 Revised:2020-12-31 Published:2021-06-01 Online:2021-08-01
  • Supported by:
    Scientific and Technological Project of China (Nos.31900916, 31870917), the Science & Technology Innovation Talents in Universities of Henan Province (No.21HASTIT041) and the Innovative Research Team of Science and Technology in University of Henan Province (No.20IRTSTHN024)

摘要: 甲酸脱氢酶(formate dehydrogenase,FDH)属于D-2-羟基酸脱氢酶类,能催化甲酸氧化生成二氧化碳,同时能将氧化型辅酶I(Oxdized form of nicotinamide adenine dinucleotide,NAD+)还原成还原型辅酶I(Redued form of nicotinamide adenine dinucleotide,NADH),在NADH的再生中起重要作用。 为了获得高活性的甲酸脱氢酶突变体,本研究以博伊丁假丝酵母甲酸脱氢酶(Candida boidinii formate dehydrogenases,CbFDH)突变体(CbFDHC23S)为亲本,进行了2轮定向进化,获得了一个比酶活性约为亲本4倍,且更适合于在生理条件下进行辅酶再生的突变体M2。 然后,利用计算机辅助的手段初步阐明了其温度特性和催化效率改变的分子机制。 最后,借助共表达策略进一步提高了突变体M2在大肠杆菌中的表达水平,超声裂解液中的甲酸脱氢酶活性达到45.85 U/mL,远远高于亲本单拷贝表达水平。 本研究为增强NADH再生能力、降低NADH的再生成本,实现FDH偶联催化的手性醇及氨基酸衍生物等食品添加剂高效、廉价的绿色生物合成奠定理论基础。

关键词: 甲酸脱氢酶, 催化效率, 定向进化, 分子对接, 高效表达

Abstract: Formate dehydrogenase (FDH) is a D-2-hydroxy acid dehydrogenase, and catalyzes the oxidation of formate to carbon dioxide, coupled with reduction of NAD+(oxidized nicotinamide adenine dinucleotide (NAD)) to NADH (reduced NAD) that plays a key role in the process of NADH regeneration. In order to obtain highly active formate dehydrogenase mutants, the Candida boidinii formate dehydrogenase CbFDHC23S was used as the parent to conduct two rounds of directional evolution, and a mutant M2 was obtained. The specific activity of M2 is about 4 times more than the parent and M2 and is more suitable for coenzyme regeneration under physiological conditions. Then, the molecular mechanism of the temperature characteristic and the catalytic efficiency change was preliminarily elucidated by the computer aided method. Finally, with the help of the co-expression strategy, the expression level of mutant M2 in Escherichia coli is further improved, and the formate dehydrogenase activity in the ultrasonic lysate reaches 45.85 U/mL, which is far higher than the expression level of the parent single copy. This study laid a theoretical foundation for the green biosynthesis of food additives such as chiral alcohols and amino acid derivatives catalyzed by FDH coupling to enhance the regeneration capacity of NADH, reduce the regeneration cost of NADH, and achieve high efficiency and low cost.

Key words: Formate dehydrogenase, Catalytic efficiency, Directed evolution, Molecular docking, Overexpression

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