title: A high effective NADH-ferricyanide dehydrogenase coupled with laccase for NAD(+) regeneration.
abstract: OBJECTIVE
  To find an efficient and cheap system for NAD(+) regeneration
  
  
  RESULTS
  A NADH-ferricyanide dehydrogenase was obtained from an isolate of Escherichia coli. Optimal activity of the NADH dehydrogenase was at 45 °C and pH 7.5, with a K m value for NADH of 10 μM. By combining the NADH dehydrogenase, potassium ferricyanide and laccase, a bi-enzyme system for NAD(+) regeneration was established. The system is attractive in that the O2 consumed by laccase is from air and the sole byproduct of the reaction is water. During the reaction process, 10 mM NAD(+) was transformed from NADH in less than 2 h under the condition of 0.5 U NADH dehydrogenase, 0.5 U laccase, 0.1 mM potassium ferricyanide at pH 5.6, 30 °C CONCLUSION: The bi-enzyme system employed the NADH-ferricyanide dehydrogenase and laccase as catalysts, and potassium ferricyanide as redox mediator, is a promising alternative for NAD(+) regeneration.
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Chengli
authors.initials: C
authors.lastname: Yang
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Xing
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Bingxin
authors.initials: B
authors.lastname: Bao
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Xuan
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China. lidali@njust.edu.cn.
authors.forename: Dali
authors.initials: D
authors.lastname: Li
authors.affiliation: Dalian Institute of Biotechnology, Liaoning Academy of Agricultural Science, Dalian, 116024, People's Republic of China.
authors.forename: Xingfan
authors.initials: X
authors.lastname: Du
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Ruofu
authors.initials: R
authors.lastname: Shi
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Junfang
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Bioengineering, Nanjing University of Science & Technology, Nanjing, 210094, People's Republic of China.
authors.forename: Ronghui
authors.initials: R
authors.lastname: Zhu
mesh_terms: D002384:Catalysis; D004926:Escherichia coli / Q000201:enzymology; D005292:Ferricyanides / Q000378:metabolism; D007700:Kinetics; D042845:Laccase / Q000378:metabolism*; D009243:NAD / Q000378:metabolism*; D009247:NADH, NADPH Oxidoreductases / Q000378:metabolism
chemical_list: D005292:Ferricyanides; D009243:NAD; D042845:Laccase; D009247:NADH, NADPH Oxidoreductases; C014227:ferricyanide reductase; C028033:potassium ferricyanide
keywords: Coenzyme regeneration; Coupled enzymes; Laccase; NAD+; NADH dehydrogenase; Potassium ferricyanide