Rat carboxylesterase ES-4 enzyme functions as a major hepatic neutral cholesteryl ester hydrolase.

摘要: Although esterification of free cholesterol to cholesteryl ester in the liver is known be catalyzed by enzyme acyl-coenzyme A:cholesterol acyltransferase, ACAT, neutral hydrolase (nCEH) that catalyzes reverse reaction has remained elusive. Because undergoes continuous cycling between and esterified forms, steady-state concentrations two species their metabolic availability for pathways, such as lipoprotein assembly bile acid synthesis, depend upon nCEH activity. On basis general characteristics family rat carboxylesterases, we hypothesized one member, ES-4, was a promising candidate hepatic nCEH. Using under- overexpression approaches, provide multiple lines evidence establish ES-4 bona fide endogenous can account majority hydrolysis transformed cells primary hepatocytes.