LCAT Protein, Human (HEK293, His)

LCAT, a pivotal enzyme in the extracellular metabolism of plasma lipoproteins, is primarily synthesized in the liver and secreted into the plasma. In this crucial role, LCAT converts cholesterol and phosphatidylcholines (lecithins) on the surface of both high and low-density lipoproteins (HDLs and LDLs) to cholesteryl esters and lysophosphatidylcholines. The resulting cholesteryl esters are transported back to the liver. LCAT exhibits a preference for plasma 16:0-18:2 or 18:O-18:2 phosphatidylcholines. Beyond its hepatic functions, LCAT is produced in the brain by primary astrocytes, where it esterifies free cholesterol on nascent APOE-containing lipoproteins secreted from glia, influencing cerebral spinal fluid (CSF) APOE- and APOA1 levels. In collaboration with APOE and the cholesterol transporter ABCA1, LCAT plays a pivotal role in the maturation of glial-derived, nascent lipoproteins. Additionally, LCAT is essential for remodeling high-density lipoprotein particles into their spherical forms and catalyzes the hydrolysis of platelet-activating factor (PAF) to lyso-PAF, as well as the esterification of (24S)-hydroxycholesterol (24(S)OH-C), known as cerebrosterol, to produce 24(S)OH-C monoesters.