Lipoprotein

Structure of a chylomicron (the largest lipoprotein).
ApoA, ApoB, ApoC, ApoE are apolipoproteins; green particles are phospholipids; T is triglyceride; C is cholesterol ester.

A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid (also known as fat) molecules in water, as in blood plasma or other extracellular fluids. They consist of a triglyceride and cholesterol center, surrounded by a phospholipid outer shell, with the hydrophilic portions oriented outward toward the surrounding water and lipophilic portions oriented inward toward the lipid center. A special kind of protein, called apolipoprotein, is embedded in the outer shell, both stabilising the complex and giving it a functional identity that determines its role.

Plasma lipoprotein particles are commonly divided into five main classes, based on size, lipid composition, and apolipoprotein content: HDL, LDL, IDL, VLDL and chylomicrons. Subgroups of these plasma particles are primary drivers or modulators of atherosclerosis.[1]

Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are sometimes also classified as lipoproteins, since they are formed by lipids and proteins.

  1. ^ Gofman JW, Jones HB, Lindgren FT, Lyon TP, Elliott HA, Strisower B (August 1950). "Blood lipids and human atherosclerosis". Circulation. 2 (2): 161–78. doi:10.1161/01.CIR.2.2.161. PMID 15427204.