Main LDL receptors is:

Ans. (b) APO B 100Ref: Harper's Biochemistry, 30th ed. pg. 254* The low-density-lipoprotein (LDL) receptor is a cell- surface protein that plays an important part in the metabolism of cholesterol by mediating the uptake of LDL from plasma into cells.* Although LDL particles bind to the LDL receptor through their apolipoprotein B (apo B) and apolipoprotein E (apo E) moieties, other apo E-containing particles, like chylomicron remnants, are not dependent on the LDL receptor for uptake into cells.* ApoB100 levels are associated with coronary heart disease, and are even a better predictor of it than is LDL level. A simple way of explaining this observation is to use the idea that ApoB-100 reflects lipoprotein particle number (independent of their cholesterol content). In this way, one can infer that the number of ApoB100- containing lipoprotein particles is a determinant of atherosclerosis and heart disease.* Most important apoprotein in HDL: Apo A-I* Most important apoprotein in chylomicrons: Apo B-48, E* Most important apoprotein in LDL, IDL, VLDL: Apo B-100* Apo protein for IDL - Apo B 100 and E