Cholesterol Esterase (EC 3.1.1.13, Porcine pancreas)

Cholesterol Esterase is found primarily in pancreas and pancreatic secretions, but in other tissues as well. Bile salts, such as cholate and its conjugates, act as stabilizers of the native polymeric form of the enzyme and can protect it from proteolytic degradation in the intestine. Cholesterol esterase is an enzyme that catalyses the hydrolysis of cholesterol and some other sterol esters to liberate cholesterol plus a fatty acid anion. The enzyme is bound to cellular membranes of excitable tissue (synaptic junction, endoplasmic reticulum, etc.). It is believed to be associated with nerve impulse conduction. , Protein Accession Number:, NP_001116606, Molecular Weight: Monomer: 65kD (8), Hexamer: 400kD (8) , Optimal pH: For esterification, 6.1-6.2, For hydrolysis, 6.6-7.0 (17). Active Site Residues: Serine (S194), Histidine (H435), Aspartate (D320), Activators: Bile Salts, Cholate, glycocholate, taurocholate (18). Inhibitors: PMSF and p-chloromercuribenzoate (8), Diisopropyl fluorophosphate (Momsen and Brockman 1976), Hg2+, Ag+, and ionic detergents, Aryl carbamates (Feaster et al. 1996), Protease: >80ug/unit, Activity (u/gm dw): >300 , Unit Definition: 1unit hydrolyzes 1umole of cholesterol ester per minute at 37ºC, pH 7.0. Concentration (A280): ~1.5mg/ml, Storage and Stability: Lyophilized powder may be stored at -20°C. Stable for 12 months at -20°C. Reconstitute with sterile 0.1M PBS. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.