Download PDF
Thromb Haemost 1982; 48(01): 024-026
DOI: 10.1055/s-0038-1657208
Original Article
Schattauer GmbH Stuttgart

Kinetics of the Reaction Between Urokinase and an Inhibitor of Fibrinolysis from Placental Tissue

Ulla Christensen
The Chemical Laboratory IV, University of Copenhagen, Copenhagen, Denmark, Department of Pediatrics, Allmänna Sjukhuset, Malmö, Sweden
The Department of Gynecology and Obstetrics, University of Lund, Lund, Sweden
,
L Holmberg
The Chemical Laboratory IV, University of Copenhagen, Copenhagen, Denmark, Department of Pediatrics, Allmänna Sjukhuset, Malmö, Sweden
The Department of Gynecology and Obstetrics, University of Lund, Lund, Sweden
,
B Bladh
The Chemical Laboratory IV, University of Copenhagen, Copenhagen, Denmark, Department of Pediatrics, Allmänna Sjukhuset, Malmö, Sweden
The Department of Gynecology and Obstetrics, University of Lund, Lund, Sweden
,
B Åstedt
The Chemical Laboratory IV, University of Copenhagen, Copenhagen, Denmark, Department of Pediatrics, Allmänna Sjukhuset, Malmö, Sweden
The Department of Gynecology and Obstetrics, University of Lund, Lund, Sweden
› Author Affiliations
Further Information

Publication History

Received 21 September 1981

Accepted 07 May 1982

Publication Date:
13 July 2018 (online)

Also available at
 PDF Download  Permissions and Reprints

Summary

The interaction of urokinase (EC 3.4.21.31) and a protein proteinase inhibitor of fibrinolysis partially purified from placental tissue, which inhibits urokinase but not plasmin, was investigated. The preparations of the inhibitor contained no other known proteinase inhibitors. It was found that a 1:1 complex is formed and that the reaction proceeds as a second order, one step process, the association rate constant of which is 4.5 106 M−1 S−1 at pH 8.4, 37° C and 3.0 106 M−1 S−1 at pH 7.3, 37° C. The binding is very tight, the dissociation constant of the inhibitor-urokinase complex was estimated to be Ki≦10−11 M.

Keywords

Placental inhibitor of fibrinolysis - Urokinase - Reaction kinetics
 

  • References

  • 1 Kawano T, Morimoto K, Uemura YJ. Urokinase inhibitor in human placenta. Nature 1968; 217: 253-254
    CrossrefPubMedSearch in Google Scholar
  • 2 Kawano T, Morimoto K, Uemura YJ. Partial purification and properties of urokinase inhibitor from human placenta. J Biochem 1970; 67: 333-342
    CrossrefPubMedSearch in Google Scholar
  • 3 Holmberg L, Lecander I, Persson B, Åstedt B. An inhibitor from placenta specifically binds urokinase and inhibits plasminogen activator released from ovarian carcinoma in tissue culture. Biochim Biophys Acta 1978; 544: 128-137
    CrossrefPubMedSearch in Google Scholar
  • 4 Åstedt B, Pandolfi M, Nilsson Inga Marie. Inhibitory effect of placenta on plasminogen activation in human organ culture. Proc Exp Biol Med 1972; 139: 1421-1424
    CrossrefPubMedSearch in Google Scholar
  • 5 Aoki N, Kawano T. Inhibition of plasminogen activators by naturally occurring inhibitors in man. Am J Physiol 1972; 233: 1334-1337
    PubMedSearch in Google Scholar
  • 6 Chase JrT, Shaw E. Comparison of the esterase activities of trypsin, plasmin and thrombin on guanidinobenzoate esters. Titration of the enzymes. Biochemistry 1969; 8: 2212-2224
    CrossrefPubMedSearch in Google Scholar
  • 7 Ipsen H-H, Christensen U. Kinetic studies of urokinase catalysed hydrolysis of 5-oxo-Pro-Gly-Arg pNA. Biochim Biophys Acta 1980; 613: 476-481
    CrossrefPubMedSearch in Google Scholar
  • 8 Holmberg L, Bladh B, Åstedt B. Purification of urokinase by affinity chromatography. Biochim Biophys Acta 1976; 445: 215-222
    CrossrefPubMedSearch in Google Scholar