Acely-CoA:cholestorl acyltransferase (ACAT) is an integral membrane enzyme that belongs to type-B carboxylesterase/lipase family. ACAT catalyzes the formation of cholesteryl esters from cholesterol and long-chain fatty-acyl-coenzyme A (1). ACAT also function as a regulator of
intracellular cholesterol homeostasis at single cell level. Two isoform of ACAT exists, ACAT1 and ACAT2, are expressed in liver and intestine. However, ACAT1 is only found in macrophages and SMCs (2). The accumulation of cholesteryl esters produced by ACAT in macrophages can lead to foam cell formation, an indication of early stage atherosclerosis. ACAT activity has been linked to Alzehimer