Biochemistry, Low Density Lipoprotein

Excerpt

Both cholesterol esters (CE) and triacylglycerols (TG) are insoluble in water (plasma); hence they are packaged as lipoproteins comprising an inner core of CE and TG with a surface coat of apolipoproteins, free cholesterol (FC), and phospholipids. Packaged as lipoproteins, they can be transported to various tissues where needed. By differing the lipid and protein concentrations, up to 5 different lipoproteins can be produced, such as chylomicrons, very-low-density lipoproteins (VLDL), intermediate-density lipoproteins (IDL), low-density lipoproteins (LDL), and high-density lipoproteins (HDL). LDL is the predominant carrier of serum cholesterol (around 67%) and delivers it to tissues of need such as the adrenal glands, gonads, and other tissues. With a density of 1.019 to 1.063 g/ml, LDL contains 20% protein and 50% cholesterol (CE and FC) and displays beta mobility on electrophoresis. This review focuses on LDL, especially its biochemistry, measurement, and clinical significance.