title: Pectin plays an important role on the kinetics properties of polyphenol oxidase from honeydew peach.
abstract: Polyphenol oxidase (PPO) was purified from peach pulp by a three-step column chromatographic procedure. The kinetics properties of the PPO fractions obtained from different purification steps were compared. All the fractions showed high affinities for (+)-catechin and (-)-epicatechin. The optimum pHs and optimum temperatures for all the fractions were the same. However, the fraction that contained pectin was more sensitive to the change of pH, and it had a lower affinity for the substrates and a higher thermostability than the fractions without pectin. In addition, the protein impurities in PPO fractions might have no effect on the properties of PPO. l-Cysteine and glutathione were effective for the inhibition of all the PPO fractions, while NaF inhibited moderately. However, the pectin could reduce the inhibition effects of those inhibitors.
authors.affiliation: Department of Biology and Food Sciences, Zhejiang Pharmaceutical College, Ningbo 315100, Zhejiang, PR China.
authors.forename: Liang
authors.initials: L
authors.lastname: Liu
authors.affiliation: College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, Zhejiang, PR China. Electronic address: shaoqiancao@sina.com.
authors.forename: Shaoqian
authors.initials: S
authors.lastname: Cao
authors.affiliation: College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, Zhejiang, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Yang
authors.affiliation: College of Biological and Environmental Sciences, Zhejiang Wanli University, Ningbo 315100, Zhejiang, PR China.
authors.forename: Xiangyang
authors.initials: X
authors.lastname: Qi
mesh_terms: D002392:Catechin / Q000378:metabolism; D004156:Catechol Oxidase / Q000737:chemistry* / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010368:Pectins / Q000737:chemistry / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry* / Q000378:metabolism; D000068239:Prunus persica / Q000737:chemistry / Q000201:enzymology*; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D010940:Plant Proteins; D010368:Pectins; D002392:Catechin; D004156:Catechol Oxidase
keywords: (+)-Catechin (PubChem CID: 9064); (−)-Epicatechin (PubChem CID: 72276); Catechol (PubChem CID: 289); Glutathione (PubChem CID: 124886); Kinetics; NaF (PubChem CID: 5235); Peach; Pectin; Polyphenol oxidase; Purification; l-Cysteine (PubChem CID: 5862)