Slotte J P, Ekman S
Biochim Biophys Acta. 1986 Nov 14;879(2):221-8. doi: 10.1016/0005-2760(86)90106-2.
The objective of this study was to examine and characterize the cholesteryl ester synthesizing [S] and hydrolyzing [H] properties of the acid cholesteryl ester hydrolase (acid cholesteryl ester hydrolase), both in isolated rat liver lysosomes and in cell-free extracts from cultured fibroblasts. For both liver lysosomes and fibroblasts extracts, the major synthesizing activity was found around pH 4 and did not require exogenous ATP. The rate of hydrolysis was measured at pH 4.5. Several different inhibitors were used in order to characterize the reactions. Ammonium chloride did not markedly affect the activity of acid cholesteryl ester hydrolase at pH 4 [S] or 4.5 [H], whereas chloroquine was a potent inhibitor of acid CEase in both liver lysosomes and fibroblast extracts. The [S] activity of the acid cholesteryl ester hydrolase in either material was not affected by the acylCoA:cholesterol acyltransferase inhibitor Compound 58-035 from Sandoz. Progesterone, on the other hand, which is an often used acylCoA:cholesterol acyltransferase inhibitor, markedly blocked both activities of the acid CEase. Our results indicate that the lysosomal compartment of both studied tissues, in addition to hydrolysis activity, also have a significant esterification activity. It appears that both activities are carried out by the same enzyme.
本研究的目的是检测并表征酸性胆固醇酯水解酶在分离的大鼠肝脏溶酶体和培养的成纤维细胞无细胞提取物中的胆固醇酯合成[S]和水解[H]特性。对于肝脏溶酶体和成纤维细胞提取物，主要的合成活性在pH 4左右被发现，且不需要外源性ATP。水解速率在pH 4.5时测定。使用了几种不同的抑制剂来表征这些反应。氯化铵在pH 4 [S]或4.5 [H]时对酸性胆固醇酯水解酶的活性没有显著影响，而氯喹是肝脏溶酶体和成纤维细胞提取物中酸性胆固醇酯酶的有效抑制剂。桑多兹公司生产的酰基辅酶A：胆固醇酰基转移酶抑制剂化合物58-035对两种材料中酸性胆固醇酯水解酶的[S]活性没有影响。另一方面，常用的酰基辅酶A：胆固醇酰基转移酶抑制剂孕酮显著阻断了酸性胆固醇酯酶的两种活性。我们的结果表明，除水解活性外，两种研究组织的溶酶体区室也具有显著的酯化活性。似乎这两种活性是由同一种酶进行的。
