11.1.4 Esterification of cholesterol
Unmodified cholesterol has a preference for a superficial location in lipid phases (e.g., membranes), such that its polar hydroxyl group is in contact with the aqueous phase. This OH group can be esterified, so that it becomes shielded by a fatty acyl residue (Figure 11.1.4-1). The fatty acyl residue is purloined from phosphatidylcholine, one of the major phospholipids in membranes and lipoproteins. The enzyme catalyzing this exchange is known as lecithin:cholesterol acyltransferase (LCAT). Cholesterol esters partition into the interior of lipoprotein particles, which greatly increases their transport capacity for cholesterol.