What is the Origin of Lipoproteins?

The term lipoprotein is a compound word derived from the Greek lipos (fat) and proteios (of the first rank), reflecting their dual composition of lipid and protein. Their structure and function were elucidated through ultracentrifugation studies in the mid-20th century, which allowed for the physical separation and characterization of different density classes. This discovery was foundational to understanding cholesterol metabolism and its link to atherosclerosis.

What is the Mechanism of Lipoproteins?

The mechanism of action involves the specific apolipoproteins on the surface of the particle, which act as ligands for cellular receptors and as cofactors for enzymes. For example, apolipoprotein B-100 on LDL facilitates its uptake by the LDL receptor in the liver and peripheral tissues, delivering cholesterol. Conversely, apolipoprotein A-I on HDL mediates reverse cholesterol transport, picking up excess cholesterol from peripheral cells and returning it to the liver for excretion, thereby exerting a protective effect on the vasculature.

Lipoproteins ∞ Area

Lipoproteins

Meaning

Lipoproteins are complex biochemical particles composed of a core of hydrophobic lipids, primarily triglycerides and cholesterol esters, surrounded by a hydrophilic shell of phospholipids, free cholesterol, and apolipoproteins. These particles are essential for the systemic transport of water-insoluble fats through the aqueous medium of the blood plasma. They are classified by density—including chylomicrons, VLDL, LDL, and HDL—with different classes reflecting varying lipid and protein compositions and distinct roles in cardiovascular health.