Lipoprotein (a)
Lipoprotein (a) resembles LDL. It differs in that another protein simlar to plasminogen is bound to apoprotein B-100 – apoprotein (a)[1],[2]. It is reported to serve to transport lipids into the endothelium[3]. Hyperlipoproteinemia Lp(a) is an independent risk factor for atherosclerosis.
The physiological significance of apoprotein (a) is unknown. This protein is only found in humans, old world monkeys and hedgehogs. As already mentioned, it shows high homology with plasminogen. Also, the genes for apoprotein (a) plasminogen are in close proximity on chromosome 6q26-27 and there is linkage between them [2]. A higher concentration of apolipoprotein (a) improves wound healing. Its degradation products have antiangiogenic activity, which is also associated with antitumor activity [2]. The antitumor effect of apo (a) and the improvement of tissue regeneration explain that high concentrations of apo (a) are associated not only with a higher risk of cardiovascular diseases, but also with longevity in some individuals [2].
