Determination of Lecithin: Cholesterol Acyltransfer in Human Blood Plasma

Abstract

A method for determining lecithin: cholesterol acyltransferase (LCAT) activity is presented. Trace amounts of labelled cholesterol are added to serum or plasma. During a preincubation time in which the LCAT is inhibited by a disulphide, the tracer equilibrates with endogenous lipoprotein cholesterol. The enzyme is reactivated by excess of thiol. The presented method seems to be a good measure for the in vivo blood plasma cholesterol esterification rate as only autologous, non-heated lipoproteins are used in the assay.

Key Words:

• Blood plasma
• human
• cholesterol
• cholesterol esterification
• enzyme activity
• enzyme inhibition
• inborn error of lipid metabolism
• lecithin
• cholesterol acyltransferase