Kluft C, Jie A F, Los P, de Wit E, Havekes L
Gaubius Institute TNO, Leiden, The Netherlands.
Biochem Biophys Res Commun. 1989 Jun 15;161(2):427-33. doi: 10.1016/0006-291x(89)92616-8.
Apolipoprotein(a), apo(a), contains 37 repeats structurally homologous to kringle 4 structures of the fibrinolysis zymogen plasminogen. The aim of the study was to explore the functional analogy between apolipoprotein(a) and plasminogen in the binding to the kringle-4-binding plasma protein, tetranectin. With a modified crossed immunoelectrophoresis technique, reversible binding between lipoprotein(a) and tetranectin could be demonstrated with an apparent Kd of 0.013 muMol/l. Lys- and Glu-plasminogen showed an apparent Kd of 0.5 muMol/l. Binding of lipoprotein(a) to fibrin and to fibrin-bound tetranectin was found to be negligible. The absence of fibrin binding of lipoprotein(a) excludes a potential mechanism of coexistence of fibrin and lipid deposits in arterial diseases and does not provide for a link between lipoprotein and the clotting system. Plasminogen and lipoprotein(a) show functional analogy in their binding to tetranectin, but tetranectin primarily targets at lipoprotein(a).
