Lipoprotein Metabolism
What is the structure of lipoprotein and their metabolism?
Lipoprotein consists of apolipoprotein, phospholipid, free cholesterol, cholesterol ester and triglyceride.
There are different types of lipoprotein: chylomicrons, VLDL, LDL, HDL.
Chylomicrons: enter bloodstream via thoracic duct – cleave by lipoprotein lipase (LPL) which is found on the surface of endothelial cells – become chylomicron remnants – bind to apoE receptor on liver cell – receptor mediated endocytosis
VLDL: produce by liver cells – enter bloodstream – cleave by LPL on endothelial cells – become VLDL remnants – VLDL remnants bind to apoE receptor and undergoes receptor mediated endocytosis or VLDL remnants being processed to LDL by hepatic lipase on the surface of liver cells – LDL can either bind to LDL receptor on liver or extrahepatic cells and undergoes receptor mediated endocytosis
HDL: produce by liver cells – enter bloodstream – transport cholesterol back from peripheral tissues to liver
Lipoprotein Physiology: HDL (4/4)
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