title: [Study on the properties of methyl parathion hydrolase from Pseudomonas sp. WBC-3].
abstract: A methyl parathion degradation enzyme, or methyl parathion hydrolase (MPH, EC 3.1.8.1), locating in the soluble intracellular fraction of Pseudomonas sp. WBC-3, was purified 49.1-fold to homogeneity by one-step ion exchange chromatography. The physical and chemical properties of the purified MPH were studied. The purified MPH displayed relatively broad optimal temperature around 40 degrees. The activity of MPH was affected by pH and the optimal pH was 11.0. Cd2+ and Fe2+ could enhance the catalytic efficiency of MPH while Hg2+, Zn2+, Al3+ and Bi3+ showed inhibition effect. With methyl parathion as the optimal substrate, the Km was 0.0807mmol/L and the kcat was 2.1 x 10(6) min(-1). In addition, the comparison of native and subunit molecular weights of MPH suggested that this enzyme was a monomer of approximate 34kD.
authors.affiliation: Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan 430071, China.
authors.forename: Xiaona
authors.initials: X
authors.lastname: Chu
authors.forename: Xianen
authors.initials: X
authors.lastname: Zhang
authors.forename: Yali
authors.initials: Y
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Liu
authors.forename: Donglin
authors.initials: D
authors.lastname: Song
mesh_terms: D004795:Enzyme Stability; D007700:Kinetics; D008743:Methyl Parathion / Q000378:metabolism; D008970:Molecular Weight; D010744:Phosphoric Monoester Hydrolases / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D011549:Pseudomonas / Q000737:chemistry* / Q000201:enzymology* / Q000235:genetics; D013379:Substrate Specificity
chemical_list: D008743:Methyl Parathion; C495424:methyl parathion hydrolase, Pseudomonas; D010744:Phosphoric Monoester Hydrolases