Thromb Haemost 1995; 73(03): 458-465
DOI: 10.1055/s-0038-1653797
Original Articles
Fibrinolysis
Schattauer GmbH Stuttgart

Interaction of Lp(a) with Plasminogen Binding Sites on Cells

Lindsey A Miles
1   The Department of Vascular Biology and Department of Immunology, The Scripps Research Institute, La Jolla, CA, USA
,
Gunther M Fless
2   Department of Medicine, University of Chicago, Chicago, IL, USA
,
Angelo M Scanu
2   Department of Medicine, University of Chicago, Chicago, IL, USA
3   Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, IL, USA
,
Patricia Baynham
1   The Department of Vascular Biology and Department of Immunology, The Scripps Research Institute, La Jolla, CA, USA
,
Matthew T Sebald
1   The Department of Vascular Biology and Department of Immunology, The Scripps Research Institute, La Jolla, CA, USA
,
Pamela Skocir
4   Center for Thrombosis and Vascular Biology (FF20), Department of Molecular Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA
,
Linda K Curtiss
1   The Department of Vascular Biology and Department of Immunology, The Scripps Research Institute, La Jolla, CA, USA
,
Eugene G Levin
1   The Department of Vascular Biology and Department of Immunology, The Scripps Research Institute, La Jolla, CA, USA
,
Jane L Hoover-Plow
4   Center for Thrombosis and Vascular Biology (FF20), Department of Molecular Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA
,
Edward F Plow
4   Center for Thrombosis and Vascular Biology (FF20), Department of Molecular Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio, USA
› Author Affiliations
Further Information

Publication History

Received14 June 1994

Accepted after resubmission 21 November 1994

Publication Date:
09 July 2018 (online)

Preview

Summary

Lp(a) competes with plasminogen for binding to cells but it is not known whether this competition is due to the ability of Lp(a) to interact directly with plasminogen receptors. In the present study, we demonstrate that Lp(a) can interact directly with plasminogen binding sites on monocytoid U937 cells and endothelial cells. The interaction of Lp(a) with these sites was time dependent, specific, saturable, divalent ion independent and temperature sensitive, characteristics of plasminogen binding to these sites. The affinity of plasminogen and Lp(a) for these sites also was similar (Kd = 1-3 μM), but Lp(a) bound to fewer sites (̴10-fold less). Both gangliosides and cell surface proteins with car- boxy-terminal lysyl residues, including enolase, a candidate plasminogen receptor, inhibited Lp(a) binding to U937 cells. Additionally, Lp(a) interacted with low affinity lipoprotein binding sites on these cells which also recognized LDL and HDL. The ability of Lp(a) to interact with sites on cells that recognize plasminogen may contribute to the pathogenetic consequences of high levels of circulating Lp(a).