Structure and Function of Serum Lipoprotein

Structure and function of human serum lipoprotein are described as follows : 1. The formation of lipoprotein is based on the hydrophobic interaction between apoprotein and lipid constituent. 2-a. Chylomicron is synthesized in the intestine cell and secreted into the blood through lymph. It is degradated by lipoprotein lipase (LPL) resulting with chylomicron remnant, which is incorporated into the liver by E receptor. 2-b. Very low density lipoprotein (VLDL) is synthesized in the liver and secreted into the blood stream. It is digested by LPL to form VLDL remnant. A part of VLDL remnant is changed to low density lipoprotein (LDL) by LPL and other part of remnant is incorporated into the liver. Resulting LDL enters partially into extrahepatic tissues by B, E receptor. 2-c. High density lipoprotein (HDL) is formed by the surface of chylomicron or VLDL. HDL is also synthesized in the liver. HDL transports cholesterol ester to VLDL or LDL after free cholesterol is transferred from cell surface of tissue to HDL, in which free cholesterol is subjected to esterification of lecithin-cholesterol acyl transferase (LCAT) of HDL. 3. High performance liquid chromatography (HPLC) analysis of serum lipoprotein has been recently performed by us. This analysis uses gel-permeation column and determination of lipid constituents in post column effluent.