PURPOSE: To obtain a uniform composition which contains a mammalian pancreatic cholesterol esterase receptor protein, inhibits the pancreatic cholesterol esterase activity promoting dietary cholesterol absorption and is useful in the treatment of atherosclerosis, etc.

CONSTITUTION: Human colon carcinoma cell lines CaCo-2 is incubated in a medium containing 20% bovine serum at 37°C for 24 hours, and then a plasma membrane fragment is isolated from CaCo-2 cells through mechanical degradation and centrifugation. This membrane is dissolved in a solution containing a surfactant or the like and fractionated through anion exchange column chromatography and cholesterol esterase affinity chromatography treatments to obtain the objective uniform composition which comprises a mammalian pancreatic cholesterol esterase receptor protein, inhibits the binding of pancreatic cholesterol esterase activity promoting dietary cholesterol absorption to its receptor and is useful in the treatment of atherosclerosis, etc.