Genetic Predisposition for Multiple Metabolic Syndrome. Part 4: Apolipoprotein E and Lipoprotein (a)

Overview

Apolipoprotein E (apo E) is a genetically polymorphous glykoprotein made up of 299 amino acids. It is an importantpart of triacylglycerol rich lipoproteins [chylomicrons, lipoproteins with a very low density (VLDL) and their„residues“]. Apo E is a ligand of apo B, E receptors and thus regulates in a marked way the homeostasis of lipidsand lipoproteins in plasma. The genetic polymorphism of apo E is controlled by three alleles e2, e3, e4 which influenceindividual plasma cholesterol levels and thus the process of atherogenesis.Lipoprotein (a) [Lp(a)] is a plasma lipoprotein which is another independent, genetically determined risk factorin the process of atherogenesis. The basis of its structure is a micelle of LDL which is linked by a disulphidic covalentwith the glycoprotein of the apolipoprotein (a). Lp (a) was detected in atherosclerotic plaques and it is assumed thatit participates in the penetration of lipids into the vascular wall. Its thrombogenic properties were also detected dueto its structural relationship with plasminogen to which it is linked and inhibits competitively the transformation ofplasminogen to plasmin.

Key words:
apolipoprotein E, homeostasis of plasma cholesterol, lipoprotein (a), apolipoprotein (a).