[Genetic predisposition for the multiple metabolic syndrome. Part 4. Apolipoprotein E and lipoprotein (a)]

Apolipoprotein E (apo E) is a genetically polymorphous glykoprotein made up of 299 amino acids. It is an important part 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 lipids and lipoproteins in plasma. The genetic polymorphism of apo E is controlled by three alleles epsilon 2, epsilon 3, epsilon 4 which influence individual plasma cholesterol levels and thus the process of atherogenesis. Lipoprotein (a) [Lp(a)] is a plasma lipoprotein which is another independent, genetically determined risk factor in the process of atherogenesis. The basis of its structure is a micelle of LDL which is linked by a disulphidic covalent with the glycoprotein of the apolipoprotein (a). Lp (a) was detected in atherosclerotic plaques and it is assumed that it participates in the penetration of lipids into the vascular wall. Its thrombogenic properties were also detected due to its structural relationship with plasminogen to which it is linked and inhibits competitively the transformation of plasminogen to plasmin.