Structural studies of discoidal lipoprotein A-I

Apolipoprotein A-I (apoA-I) is a major exchangeable apolipoprotein of high-density lipoproteins (HDLs), and plays an important role in reverse cholesterol transport. This process involves transport of cholesterol from peripheral tissues to the liver for processing, thereby eliminating excess cholesterol from the body. The function of apoA-I and its interaction with other components of HDL, including lecithin-cholesterol acyltransferase, seems to be closely linked to its structural plasticity. ApoA-I is likely to undergo changes in its structure and orientation between the various HDL subclasses and, therefore, knowledge of the precise structure of apoA-I is essential for understanding its role in the antiatherogenic properties of HDL. This review focuses on the role of apoA-I in reverse cholesterol transport and the work done by various groups to determine the structure of apoA-I in discoidal HDL particles.