Thromb Haemost 1985; 54(04): 750-755
DOI: 10.1055/s-0038-1660125
Original Article
Schattauer GmbH Stuttgart

Human Leucocyte Urokinase Inhibitor - Purification, Characterization and Comparative Studies Against Different Plasminogen Activators[*]

M Kopitar
1   The Department of Biochemistry, J. Stefan Institute, Ljubljana, Yugoslavia
,
B Rozman
2   The Medical Faculty, E. Kardelj University of Ljubljana, Ljubljana, Yugoslavia
,
J Babnik
1   The Department of Biochemistry, J. Stefan Institute, Ljubljana, Yugoslavia
,
V Turk
1   The Department of Biochemistry, J. Stefan Institute, Ljubljana, Yugoslavia
,
D E Mullins
3   The Department of Cell Biology, New York University Medical Center, New York, N.Y., USA
,
T C Wun
4   The Rockefeller University, New York, N.Y., USA
› Author Affiliations
Further Information

Publication History

Received 19 February 1985

Accepted 12 August 1985

Publication Date:
19 July 2018 (online)

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Summary

A plasminogen activator inhibitor (PA-I) which inhibits primarily plasminogen activator of the urokinase type (u-PA) was isolated from the cytosol of human peripheral leukocytes. The inhibitor was isolated using ion exchange chromatography, gel filtration and FPLC. This inhibitor has an apparent molecular weight of 45 kDa, determined by SDS-PAGE, and a pi of 5.5-5.7. The inhibitor is a fast reacting inhibitor, is thermally unstable and is inactivated outside the pH range 7-9. Treatment of cytosol to pH 9 for 30 min at 37° C resulted in a large increase in inhibitory activity. Antibodies against human placental UK-I completely quenched the inhibitory activity of human leucocyte UK-I.

* Supported by a grant from the Research Council of Slovenia and 3by a grant from the National Cancer Institute (CA 23753) to D. B. Rifkin