Fernandez C J, Lacort M, Gandarias J M, Ochoa B
Biochem Biophys Res Commun. 1987 Aug 14;146(3):1212-7. doi: 10.1016/0006-291x(87)90777-7.
Lateral and transversal distribution of cholesterol ester hydrolase activity in rat liver microsomal membranes has been studied. Total cholesterol ester hydrolase activity was found predominantly (75%) in rough microsomes though specific esterase activities were similar in rough and smooth microsomal fractions. The transversal asymmetry of the enzyme was examined using the criteria of protease sensitivity and latency of mannose-6-phosphate phosphatase. Cholesterol ester hydrolase resulted drastically inhibited by proteolysis with trypsin when microsomal integrity had been previously disrupted with sodium deoxycholate or sodium taurocholate. Under these conditions, most lumenal mannose-6-phosphate phosphatase activity was destroyed. However, cholesterol esterase was unaffected by preincubating microsomes with the detergent alone, which led to the complete expression of latent mannose-6-phosphate phosphatase or by preincubating them with trypsin, where less than a 15% of the lumenal mannose-6-phosphate phosphatase was lost. These findings suggest that cholesterol ester hydrolase activity is located on the lumenal surface of the hepatic microsomal vesicles.
对大鼠肝脏微粒体膜中胆固醇酯水解酶活性的横向和纵向分布进行了研究。尽管粗糙微粒体和光滑微粒体部分的特异性酯酶活性相似，但总胆固醇酯水解酶活性主要（75%）存在于粗糙微粒体中。使用蛋白酶敏感性和甘露糖-6-磷酸磷酸酶的潜伏性标准来检查该酶的横向不对称性。当微粒体完整性先前已被脱氧胆酸钠或牛磺胆酸钠破坏时，胆固醇酯水解酶会被胰蛋白酶的蛋白水解作用显著抑制。在这些条件下，大多数腔内甘露糖-6-磷酸磷酸酶活性被破坏。然而，胆固醇酯酶不受仅用去污剂预孵育微粒体的影响，这会导致潜伏性甘露糖-6-磷酸磷酸酶完全表达，也不受用胰蛋白酶预孵育微粒体的影响，此时腔内甘露糖-6-磷酸磷酸酶损失不到15%。这些发现表明胆固醇酯水解酶活性位于肝微粒体囊泡的腔表面。
