title: Purification of lactoperoxidase from bovine whey and investigation of kinetic parameters.
abstract: BACKGROUND
  Lactoperoxidase (LPO) is related to mammalian peroxidase family which contains a wide spectrum of biological activities. Despite the wide studies on the LPO, there is little study has been performed to simplify and shorten the procedure of enzyme purification. The aim of this project was to purify the enzyme through a simple method, and investigating enzyme kinetic parameters.
  
  
  METHODS
  LPO was purified from bovine whey through modified method of Yoshida (1990) using two steps of ammonium sulfate precipitation and ion-exchange chromatography. The purity of isolated enzyme was monitored by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).
  
  
  RESULTS
  The enzyme was purified 59.13-fold with a recovery of 10.26 having a specific activity of 5.78 U/mg protein and an Rz value of 0.8. The enzyme activity was measured using guaiacol as a chromogenic substrate in phosphate buffer pH 6. SDS-PAGE showed a single bond with molecular weight of 78 kDa. The purified enzyme displayed optimum activity at pH 6 in 30 mM phosphate buffer and at a temperature of 50°C, with a Kmvalue of 178 mM and Vmax0.63 U/ml.min for guaiacol.
  
  
  CONCLUSIONS
  Using only one step ion-exchange chromatography, LPO was isolated from bovine whey in high purity.
authors.affiliation: Department of Clinical Biochemistry, Bioinformatics Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Borzouee
authors.affiliation: Department of Clinical Biochemistry, Bioinformatics Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Mohammad Reza
authors.initials: MR
authors.lastname: Mofid
authors.affiliation: Department of Pharmaceutics, School of Pharmacy and Novel Drug Delivery Systems Research Centre, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Jaleh
authors.initials: J
authors.lastname: Varshosaz
authors.affiliation: Department of Clinical Biochemistry, Bioinformatics Research Center, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran.
authors.forename: Seyed Ziyae Aldin
authors.initials: SZ
authors.lastname: Samsam Shariat
keywords: Bovine milk; enzyme; kinetic parameters; lactoperoxidase; purification; whey