title: Porcine pancreas: a superior source of cholesterol esterase for total serum cholesterol assay by the enzymatic kinetic method.
abstract: BACKGROUND
  Accurate determination of cholesterol requires complete hydrolysis of cholesteryl esters and must be very fast for the kinetic cholesterol assay. We investigated the properties of cholesterol esterase derived from Pseudomonas fluorescens, Candida cylindracea, bovine pancreas, and porcine pancreas for cholesterol determination in human serum.
  
  
  METHODS
  Optimization of four enzymes and effect of sodium cholate concentration were performed. We evaluated and compared their performances in enzymatic kinetic cholesterol determination.
  
  
  RESULTS
  The optimal sodium cholate concentration was 3, 5, 15, and 12 mmol/l with the enzyme activities at 200, 100, 100, and 100 U/l for P. fluorescens, C. cylindracea, bovine pancreas, and porcine pancreas, respectively. Linearity obtained from all enzymes was up to 16.3 mmol/l. All assays were compared favorably with standardized endpoint method. Only the cholesterol esterase derived from porcine pancreas demonstrated acceptable precision within the acceptable criteria (%CV < 3.0). Also, this esterase was least affected by interfering substances and showed longer stability than that of C. cylindracea and bovine pancreas.
  
  
  CONCLUSIONS
  Porcine pancreas cholesterol esterase is superior to that obtained from P. fluorescens, C. cylindracea, and bovine pancreas for total serum cholesterol determination by the kinetic method because of its lower cost, better accuracy and precision, less interference, and longer stability.
authors.affiliation: Faculty of Medicine, Division of Clinical Chemistry, Department of Pathology, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. srisawasdiP@yahoo.com
authors.forename: Pornpen
authors.initials: P
authors.lastname: Srisawasdi
authors.forename: Noppadol
authors.initials: N
authors.lastname: Prasertsincharoen
authors.forename: Martin H
authors.initials: MH
authors.lastname: Kroll
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D001663:Bilirubin / Q000737:chemistry; D002175:Candida / Q000201:enzymology; D002417:Cattle; D002784:Cholesterol / Q000097:blood* / Q000378:metabolism; D004355:Drug Stability; D057075:Enzyme Assays / Q000379:methods*; D004795:Enzyme Stability; D005656:Fungal Proteins / Q000737:chemistry / Q000378:metabolism; D006454:Hemoglobins / Q000737:chemistry; D006801:Humans; D007700:Kinetics; D016018:Least-Squares Analysis; D010179:Pancreas / Q000201:enzymology*; D011549:Pseudomonas / Q000201:enzymology; D015203:Reproducibility of Results; D020358:Sodium Cholate / Q000737:chemistry; D002787:Sterol Esterase / Q000737:chemistry* / Q000378:metabolism; D013552:Swine
chemical_list: D001426:Bacterial Proteins; D005656:Fungal Proteins; D006454:Hemoglobins; D002784:Cholesterol; D002787:Sterol Esterase; D020358:Sodium Cholate; D001663:Bilirubin