Description
General description
Cholesterol Esterase from bovine pancreas is a member of α-β hydrolase superfamily. The core of the protein comprises 11 β-strands, surrounded by 15 α-strands. Catalytic triad is in the centre of the molecule. The C-terminus possesses hydrophobic residues.
Application
Cholesterol Esterase from bovine pancreas has been used:
in γ-oryzanol-hydrolyzing activity
in cholesterol esterase enzyme activity for quantification of cholesterol and cholesterol esters associated in tear film and lenses samples
to test in vitro degradation of poly(fumaroyl bioxirane) maleate (PFM) polymer designed for bone tissue engineering
Enzyme responsible for the hydrolysis of many of the fatty acid esters of cholesterol.
Optimum pH range: 6-8
Activators: Bisphenol A diglycidyl ether, cAMP-dependent protein kinase type II, ethanol, methanol, n-butanol, phosphatidylcholine, phosphatidylethanolamine, sodium taurocholic acid
Inhibitors: Bisphenol A methacrylate, diisopropylfluorophosphate, enolase, Hg2+, sodium fluoride, phosphatidic acid, phosphatidylcholine, phosphatidylserine
Cholesterol esterase bound to membrane-associated heparin on brush border membranes aids in the transport of cholesterol and free fatty acid across the membrane. This enzyme is widely used in the determination of serum cholesterol in clinical laboratories. The enzyme from Sigma has been used to evaluate the inhibitory and antioxidant functions of the methanol extract of the Camellia sinensis leaves under in vitro conditions. The enzyme has also been used to digest human serum samples to confirm the presence and position of acyl esters of 7α-hydroxycholesterol.
Biochem/physiol Actions
Cholesterol esterase (CE) is a reversible enzyme that can hydrolyze or synthesize fatty acid esters of cholesterol and other sterols. Hydrolysis of water insoluble long chain fatty acid esters requires bile salt activation. Hydrolysis of water soluble esters of short chain fatty acids and lysophospholipids does not require activation by bile salts. It also hydrolyzes tri-, di-, and mono-acylglycerols, phospholipids, lysophospholipids, and ceramide. This monomeric glycoprotein may have multiple functions in lipid and lipoprotein metabolism, as well as in atherosclerosis. Its molecular mass is found to be 84 kDa.
Physical form
This product is partially purified from bovine pancreas and is supplied as a white to light brown lyophilized powder containing ≥20% protein (biuret) and potassium phosphate.
Preparation Note
Cholesterol esterase is soluble in 0.4 M potassium phosphate, pH 7.0 at 1 mg/mL concentration.
Analysis Note
Protein determined by biuret.
Other Notes
One unit will hydrolyze 1.0 μmole of cholesteryl oleate to cholesterol and oleic acid per minute at pH 7.0 at 37 °C in the presence of taurocholate.
Partially purified
