title: Prokaryotic expression and purification of Camellia sinensis polyphenol oxidase.
abstract: BACKGROUND
  Polyphenol oxidase (PPO) causes the postharvest loss of fruits and vegetables but is also a key factor in the quality development of tea. However, there are no reports on engineered active plant PPO purified from prokaryotic cells.
  
  
  RESULTS
  In this study the ppo gene of about 1800 bp from Camellia sinensis cv. Yihongzao was successfully cloned and expressed in Escherichia coli. The PPOs purified from both the soluble fraction and the inclusion bodies showed activity. In addition, 1.0 × 10(-7) mol L(-1) Cu(2+) and acidic conditions were found to be favourable for the engineered PPO catalysis of catechol oxidation.
  
  
  CONCLUSIONS
  This paper represents the first report on C. sinensis ppo expression in E. coli and engineered active PPO purification. The results of the study provide a basis for the large-scale preparation and application of PPO.
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Tea Science Department of Horticulture and Forestry Science College, Huazhong Agricultural University, Wuhan City 430070, China.
authors.forename: Jing-wei
authors.initials: JW
authors.lastname: Liu
authors.forename: You-yi
authors.initials: YY
authors.lastname: Huang
authors.forename: Jian
authors.initials: J
authors.lastname: Ding
authors.forename: Cong
authors.initials: C
authors.lastname: Liu
authors.forename: Xiu-dan
authors.initials: XD
authors.lastname: Xiao
authors.forename: De-jiang
authors.initials: DJ
authors.lastname: Ni
mesh_terms: D028241:Camellia sinensis / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D004156:Catechol Oxidase / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002396:Catechols / Q000378:metabolism*; D003001:Cloning, Molecular / Q000379:methods; D004926:Escherichia coli / Q000235:genetics* / Q000378:metabolism; D015870:Gene Expression; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D010084:Oxidation-Reduction; D010936:Plant Extracts / Q000378:metabolism*; D010941:Plant Tumors
chemical_list: D002396:Catechols; D010936:Plant Extracts; D004156:Catechol Oxidase; C034221:catechol