Lecithin–cholesterol acyltransferase (LCAT, also called phosphatidylcholine–sterol O-acyltransferase) is an enzyme found in many animals, including humans. It converts free cholesterol into cholesteryl ester, a more hydrophobic form of cholesterol. This process sequesters cholesterol ester into the core of a lipoprotein particle, eventually making the newly synthesized HDL spherical and forcing the reaction to become unidirectional since the particles are removed from the surface. The enzyme is bound to high-density lipoproteins (HDLs) (alpha-LCAT) and LDLs (beta-LCAT) in the blood plasma. LCAT deficiency can cause impaired vision due to cholesterol corneal opacities, anemia, and kidney damage. It belongs to the family of phospholipid:diacylglycerol acyltransferases.
