Patsch W, Rindler-Ludwig R, Sailer S, Braunsteiner H
Biochim Biophys Acta. 1980 May 28;618(2):337-46. doi: 10.1016/0005-2760(80)90040-5.
Hydrolysis of cholesterol oleate and glycerol trioleate was measured in homogenates of human leucocytes at optimum pH of 4.0 and 5.25, respectively. Both enzyme activities appeared to reside in the 15,000 x g, 20-min fraction of mononuclear leucocytes. Solubilization of cholesterol ester hydrolase activity was strongly dependent on the detergent to protein ratio, showing optimal solubilization at weight ratios of 1.0 in cell homogenates and of 3.0 in the 15,000 x g, 20-min fraction, whereas solubilization of glycerol ester hydrolase was independent to protein ratio over the tested range of 0.3 to 5.8. Using a sequential solubilization procedure, about 60% of the granule proteins as well as 88% of glycerol ester hydrolase activity were solubilized at a detergent to protein ratio of 0.3, whereas cholesterol ester hydrolase activity was solubilized from the remaining membranes at a ratio of about 3.0. Thus, the acid glycerol ester hydrolase and acid cholesterol ester hydrolase were related to different proteins. Since solubilization of cholesterol ester hydrolase required drastic treatment, it is suggested that this enzyme is related to a protein within the lysosomal membrane.
分别在最适pH值4.0和5.25条件下，测定了人白细胞匀浆中胆固醇油酸酯和甘油三油酸酯的水解情况。两种酶活性似乎都存在于单核白细胞15,000×g、20分钟离心后的组分中。胆固醇酯水解酶活性的增溶强烈依赖于去污剂与蛋白质的比例，在细胞匀浆中重量比为1.0时显示出最佳增溶效果，在15,000×g、20分钟离心后的组分中重量比为3.0时最佳，而甘油酯水解酶的增溶在0.3至5.8的测试比例范围内与蛋白质比例无关。采用连续增溶程序，在去污剂与蛋白质比例为0.3时，约60%的颗粒蛋白以及88%的甘油酯水解酶活性被增溶，而胆固醇酯水解酶活性则以约3.0的比例从剩余膜中增溶。因此，酸性甘油酯水解酶和酸性胆固醇酯水解酶与不同的蛋白质相关。由于胆固醇酯水解酶的增溶需要剧烈处理，提示该酶与溶酶体膜内的一种蛋白质相关。
