SOURCE. Human pancreas.
Lyophilized powder contains ca. 50% solids, comprising pH 6 buffer salts and sodium cholate. MW = 310000.
55-65 units per mg of protein.
One unit will hydrolyze 1 µmole of cholesterol acetate per minute at pH 7 at 37°C.
3ml KPO4 pH 7.0 containing 0.11 M NaCholate, 0.70 mM cholesterol acetate, 0.75 mM 4-aminoantipyrine, 4.8 mM Phenol, 15 units horseradish peroxidase and 0.30 units of cholesterol oxidase.
Equilibrate 3.0 ml of assay buffer to 37°C in a 10 mm cuvette. Add .01 - .03 units CE. Read increase in A505 starting 2 minutes after the addition of CE.
E for 1 mM hydrolyzed cholesterol acetate = 6.8