title: [Determination of paraoxonase activities in serum and HDL].
abstract: OBJECTIVE
  [corrected] To establish a reliable method of determining the activity of paraoxonase(PON) in serum and high density lipoprotein(HDL).
  
  
  METHODS
  We used phenylacetate(PA) as substrate and investigated the hydrolysis of PA catalyzed by serum PON or HDL-PON. The PON activities were calculated from the velocities of reaction that had been determined by the increasing absorbance of product p-phenol within the first 5 minutes.
  
  
  RESULTS
  Through the studies on the effects of substrate concentration, pH, activator Ca2+, and inhibitor EDTA, we found the best conditions of reaction to be: substrate concentration 5 mmol/L, pH8.0, and Ca2+ concentration 2 mmol/L. And we established the method with good reproducibility and stability.
  
  
  CONCLUSIONS
  Under the above-stated conditions, it is reliable to determine the activity of paraoxonase in serum and HDL.
authors.affiliation: Apolipoproteins Research Unit, Institute of Biochemistry and Molecular Biology, WCUMS, Chengdu 610041, China.
authors.forename: Q
authors.initials: Q
authors.lastname: Fu
authors.forename: B
authors.initials: B
authors.lastname: Liu
mesh_terms: D043303:Aryldialkylphosphatase; D004950:Esterases / Q000097:blood*; D006801:Humans; D008075:Lipoproteins, HDL / Q000737:chemistry*; D013053:Spectrophotometry
chemical_list: D008075:Lipoproteins, HDL; D004950:Esterases; D043303:Aryldialkylphosphatase