Lecithin-cholesterol acyltransferase (LCAT) as a plasma glycoprotein: an overview

This article reviews recent major efforts towards understanding the importance of carbohydrate chains for the physiological functioning of lecithin-cholesterol acyltransferase (LCAT), the plasma enzyme which esterifies cholesterol. The assembly of oligosaccharide chains in protein backbones is the most extensive of all the post-translational modifications, and can play a crucial role in protein folding, oligomer assembly and secretion, in regulating biological activity, as well as in clearance of glycoproteins from the bloodstream. Here, we describe modifications in LCAT-linked carbohydrate structures, arising from site-directed mutagenesis or from use of drugs and specific enzymes, which modify either the structure or the assembly of LCAT glycans, and evaluate how these help define their involvement in and importance to enzyme secretion, stability and activity.