intermediate-density lipoprotein particle remodeling

Definition

Target type: biologicalprocess

The acquisition, loss or modification of a protein or lipid within an intermediate-density lipoprotein particle. [GOC:BHF, GOC:expert_pt, GOC:mah, GOC:rl]

Intermediate-density lipoprotein (IDL) particle remodeling is a complex process that involves the transformation of IDL particles into low-density lipoprotein (LDL) particles. IDL particles are formed in the liver from very-low-density lipoprotein (VLDL) particles through the action of lipoprotein lipase. They are larger and denser than VLDL particles and contain a higher proportion of triglycerides. IDL particles undergo remodeling in the blood circulation, where they are further metabolized into LDL particles.

The remodeling process involves several key steps:

1. **Triglyceride hydrolysis:** IDL particles are rich in triglycerides. Triglycerides are broken down by the enzyme hepatic lipase into glycerol and free fatty acids. This process reduces the triglyceride content of IDL particles.
2. **Cholesteryl ester transfer protein (CETP) activity:** CETP is a plasma protein that mediates the exchange of cholesteryl esters between different lipoprotein particles. CETP transfers cholesteryl esters from HDL particles to IDL particles. This increases the cholesterol content of IDL particles.
3. **Cholesteryl ester hydrolase (CEH) activity:** CEH is an enzyme that hydrolyzes cholesteryl esters into free cholesterol. CEH activity in IDL particles reduces the cholesteryl ester content and increases the free cholesterol content.
4. **Lipoprotein lipase (LPL) activity:** LPL is an enzyme that hydrolyzes triglycerides in IDL particles. LPL activity is lower in IDL particles compared to VLDL particles. This contributes to the slower clearance of IDL particles from the circulation.

The remodeling of IDL particles into LDL particles is a continuous process that occurs in the blood circulation. The process is influenced by several factors, including the activity of enzymes, the concentration of plasma proteins, and the metabolic status of the individual.

During IDL remodeling, the IDL particle undergoes a series of changes, resulting in a smaller and denser particle with a higher proportion of cholesterol. The remodeled particle is then classified as an LDL particle.

LDL particles are the main carriers of cholesterol in the blood. They deliver cholesterol to cells throughout the body. However, high levels of LDL cholesterol can lead to the accumulation of cholesterol in the arteries, which can increase the risk of cardiovascular disease.'
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Proteins (1)

Compounds (2)