Lecithin-Cholesterol Acyltransferase: Assay of Cholesterol Esterification and Phospholipase A2 Activities

Lecithin:cholesterol acyltransferase (LCAT; EC 2.3.1.43) is a 67 kDa glycoprotein that is responsible for cholesterol esterification in plasma (1 ). LCAT has an important physiological role in the maturation of nascent, discoidal high density lipoproteins (HDL) to mature, spherical HDL, through the generation of a cholesteryl ester (CE)-enriched core (2 ,3 ). The enzyme has also been implicated in the reverse cholesterol transport pathway, which results in the net transport of cholesterol from peripheral tissues back to the liver for excretion (1 ,4 ). The central role of LCAT in these physiological processes is supported by the finding of plasma and tissue accumulation of free cholesterol and the presence of nascent, discoidal HDL particles in the plasma of familial LCAT-deficient subjects (5 ).