Reverse cholesterol transport is the process by which peripheral cholesterol is delivered to the liver for excretion. Which plasma enzyme is essential for the maturation of nascent HDL (disc-shaped) to spherical mature HDL by esterifying cholesterol in the HDL particle?

• A Cholesterol ester transfer protein (CETP)
• B Hepatic lipase
• C Lecithin-cholesterol acyltransferase (LCAT) ✓
• D Phospholipid transfer protein (PLTP)

Explanation

LCAT, activated by Apo A-I, transfers a fatty acid from phosphatidylcholine to free cholesterol, forming cholesterol esters within HDL. These nonpolar esters migrate to the HDL core, converting the disc-shaped nascent particle into a spherical mature HDL3 and then HDL2. This process drives net cholesterol efflux from cells down its concentration gradient. CETP transfers cholesterol esters from HDL to VLDL/LDL in exchange for triglycerides but does not itself esterify cholesterol. LCAT deficiency causes fish-eye disease with corneal opacity and low HDL.

Reference: Harper's Illustrated Biochemistry, 32nd ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.