Isolation of LP (a) from Human Serum Lipoproteins and its Sialic Acid Concentration

Lp (a), a genetic variant of -lipoproteins (LDL) was isolated from human serum and was characterized to study its behavior and sialic acid concentration. Like LDL, Lp (a) also contains significant amounts of sialic acid which can be digested completely by neuraminidase enzyme treatment for 24 hours at 370C. Thus, Lp (a) samples treated with neuraminidase for 24 or 48 hours at 370C showed negligible amounts of sialic acid. The electrophoretic mobility of these Lp (a) samples decreased in comparison to the native or untreated Lp (a) samples. Presence of high amounts of sialic acid in Lp (a) like that in LDL suggest that this carbohydrate moiety may play some role in these lipoproteins.