Thromb Haemost 1997; 77(01): 137-142
DOI: 10.1055/s-0038-1655921
Fibrinolysis
Schattauer GmbH Stuttgart

Enhancement of Plasminogen Binding to U937 Cells and Fibrin by Complestatin

Kiyoshi Tachikawa
The Department of Applied Biological Science, Tokyo Noko University, Fuchu, Tokyo, Japan
,
Keiji Hasurni
The Department of Applied Biological Science, Tokyo Noko University, Fuchu, Tokyo, Japan
,
Akira Endo
The Department of Applied Biological Science, Tokyo Noko University, Fuchu, Tokyo, Japan
› Author Affiliations
Further Information

Publication History

Received 16 January 1996

Accepted after resubmisssion 30 September 1996

Publication Date:
11 July 2018 (online)

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Summary

Plasminogen binds to endothelial and blood cells as well as to fibrin, where the zymogen is efficiently activated and protected from inhibition by α2-antiplasmin. In the present study we have found that complestatin, a peptide-like metabolite of a streptomyces, enhances binding of plasminogen to cells and fibrin. Complestatin, at concentrations ranging from 1 to 5 μM, doubled 125I-plasminogen binding to U937 cells both in the absence and presence of lipoprotein(a), a putative physiological competitor of plasminogen. The binding of 125I-plasminogen in the presence of complestatin was abolished by e-aminocaproic acid, suggesting that the lysine binding site(s) of the plasminogen molecule are involved in the binding. Equilibrium binding analyses indicated that complestatin increased the maximum binding of 125I-plasminogen to U937 cells without affecting the binding affinity. Complestatin was also effective in increasing 125I-plasminogen binding to fibrin, causing 2-fold elevation of the binding at ~1 μM. Along with the potentiation of plasminogen binding, complestatin enhanced plasmin formation, and thereby increased fibrinolysis. These results would provide a biochemical basis for a pharmacological stimulation of endogenous fibrinolysis through a promotion of plasminogen binding to cells and fibrin.