PMID: 11341506May 9, 2001Paper

Binding of recombinant apolipoprotein(a) to human platelets and effect on platelet aggregation

Thrombosis and Haemostasis
C MartínezEduardo Anglés-Cano

Abstract

The interaction of lipoprotein(a) [Lp(a)] with platelets is not well defined, particularly with regards to the individual contribution of the protein components of Lp(a), the apo B-100 and the apolipoprotein apo(a). This study investigated the binding of different recombinant apo(a) [r-apo(a)] isoforms, to human platelets and its effect on platelet aggregation. Scatchard analysis of saturation binding experiments demonstrated that human platelets display a single class of high affinity r-apo(a) binding sites (71 +/- 46 molec./platelet, Kd = 5.6 +/- 2.0 nmol/L). Platelet activation with strong agonists (thrombin, arachidonic acid) increased 2- to 10-fold the r-apo(a) binding, without affecting the affinity. Competition assays showed that the binding sites are highly specific for r-apo(a) and Lp(a). At high concentration t-PA could also bind to the r-apo(a) binding sites. By contrast, neither fibrinogen nor plasminogen inhibited to the r-apo(a) binding. The lysine analogue EACA inhibits the binding of r-apo(a) to platelets, thus suggesting the involvement of lysine residues in that interaction. Moreover, the r-apo(a) binding to platelets is unlikely mediated by GPIIb/IIIa-attached fibrin since it is not affected by platelet treat...Continue Reading

Related Concepts

Related Feeds

ApoE, Lipids & Cholesterol

Serum cholesterol, triglycerides, apolipoprotein B (APOB)-containing lipoproteins (very low-density lipoprotein (VLDL), immediate-density lipoprotein (IDL), and low-density lipoprotein (LDL), lipoprotein A (LPA)) and the total cholesterol/high-density lipoprotein (HDL) cholesterol ratio are all connected in diseases. Here is the latest research.