spherical high-density lipoprotein particle

Definition

Target type: cellularcomponent

A mature high-density lipoprotein (HDL) particle, converted from discoidal HDL particles following the esterification of cholesterol in the particle by phosphatidylcholine-sterol O-acyltransferase (lecithin cholesterol acyltransferase; LCAT). [GOC:BHF, GOC:expert_pt, GOC:mah, GOC:rl]

Spherical high-density lipoprotein (HDL) particles are complex structures composed of a core of cholesteryl esters and triglycerides surrounded by a phospholipid monolayer. This monolayer is studded with apolipoproteins, primarily apolipoprotein A-I (apoA-I). The specific cellular component of an HDL particle can be broken down as follows:

* **Core:** This central region contains hydrophobic molecules like cholesteryl esters and triglycerides. These molecules are the primary cargo of HDL particles, which are transported from peripheral tissues to the liver for metabolism.
* **Phospholipid monolayer:** This single layer of phospholipids surrounds the core and is responsible for the overall spherical shape of the particle. The polar head groups of the phospholipids face outward towards the aqueous environment, while the hydrophobic tails are embedded in the core.
* **Apolipoproteins:** These proteins are embedded in the phospholipid monolayer. The most abundant apolipoprotein in HDL is apoA-I, which plays a critical role in HDL metabolism and function. Other apolipoproteins found in HDL include apoA-II, apoC-I, apoC-II, apoC-III, apoD, and apoE.

The specific arrangement of these components contributes to the unique properties of HDL particles. The hydrophobic core allows for the efficient transport of lipids, while the phospholipid monolayer provides structural integrity and facilitates interaction with cell membranes. The apolipoproteins play a crucial role in the metabolism and function of HDL, interacting with enzymes and receptors to regulate lipid transport and reverse cholesterol transport.'
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Proteins (1)

Compounds (20)