Cholesteryl ester transfer protein

Cholesteryl ester transfer protein (CETP) is a plasma protein that facilitates the transport of cholesteryl esters and triglycerides between the lipoproteins. It collects triglycerides from very-low-density (VLDL) or low-density lipoproteins (LDL) and exchanges them for cholesteryl esters from high-density lipoproteins (HDL), and vice versa.

Function

CETP plays a crucial role in the reverse cholesterol transport pathway, which is the process by which excess cholesterol is removed from peripheral tissues and returned to the liver for excretion. By transferring cholesteryl esters from HDL (where they are abundant) to VLDL and LDL (where they are needed), CETP helps to maintain the balance of these lipids in the body.

Structure

The CETP molecule is a hydrophobic glycoprotein with a molecular weight of approximately 74 kDa. It is composed of a single polypeptide chain and does not have any known enzymatic activity. The structure of CETP is unique among the plasma lipoproteins, as it is the only one that can bind to and transfer lipids between lipoproteins.

Clinical significance

Alterations in CETP activity can have significant effects on plasma lipoprotein distribution and function. For example, genetic mutations that reduce CETP activity are associated with increased HDL cholesterol levels, which is generally considered protective against atherosclerosis. However, some studies have suggested that reduced CETP activity may actually increase the risk of cardiovascular disease, possibly due to changes in the quality of HDL particles.

On the other hand, increased CETP activity can lead to decreased HDL cholesterol levels and increased LDL cholesterol levels, which are risk factors for atherosclerosis. Therefore, CETP is a potential target for the treatment of dyslipidemias and cardiovascular disease. Several CETP inhibitors have been developed for this purpose, but their clinical efficacy and safety are still under investigation.

See also

• Lipoprotein
• Cholesterol
• Atherosclerosis
• Cardiovascular disease