title: Effect of dilution on high-density lipoprotein associated paraoxonase-1 activity.
abstract: OBJECTIVE
  To investigate the effects of dilution on high-density lipoprotein (HDL) associated paraoxonase-1 (PON1) activity.
  
  
  METHODS
  HDL was prepared by ultracentrifugation, diluted with TRIS buffer pH 8.2 (0-128 fold) and assayed spectrophotometrically for PON1 activity using paraoxon and phenyl acetate.
  
  
  RESULTS
  HDL-PON1 activity increased progressively with dilution to over 200% of the undiluted activity by 128 fold dilution (P<0.001). Conversely HDL size decreased.
  
  
  CONCLUSIONS
  These results indicate the urgent need to standardise conditions for measuring PON1 activity.
authors.affiliation: PONTECH ART, Calle de L'Argelagar, 43840 Salou, Tarragona, Spain. mike.mackness@gmail.com
authors.forename: Mike
authors.initials: M
authors.lastname: Mackness
authors.forename: Bharti
authors.initials: B
authors.lastname: Mackness
mesh_terms: D000818:Animals; D043303:Aryldialkylphosphatase / Q000032:analysis* / Q000378:metabolism*; D002623:Chemistry Techniques, Analytical / Q000592:standards; D008076:Cholesterol, HDL / Q000378:metabolism; D006801:Humans; D008075:Lipoproteins, HDL / Q000378:metabolism*; D010261:Paraoxon / Q000378:metabolism; D012756:Sheep
chemical_list: D008076:Cholesterol, HDL; D008075:Lipoproteins, HDL; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human; D010261:Paraoxon