Thromb Haemost 1982; 48(03): 257-259
DOI: 10.1055/s-0038-1657274
Original Article
Schattauer GmbH Stuttgart

Kinetics of the Inhibition of Plasmin in Acidified Human Plasma

H R Lijnen
The Center for Thrombosis and Vascular Research, Department of Medical Research, University of Leuven, Belgium
,
M Maes
The Center for Thrombosis and Vascular Research, Department of Medical Research, University of Leuven, Belgium
,
M Castel
*   Laboratoire Central d'Hématologie, Hôtel-Dieu, Paris, France
,
M Samama
*   Laboratoire Central d'Hématologie, Hôtel-Dieu, Paris, France
,
D Collen
The Center for Thrombosis and Vascular Research, Department of Medical Research, University of Leuven, Belgium
› Author Affiliations
Further Information

Publication History

Received 07 June 1982

Accepted 07 September 1982

Publication Date:
13 July 2018 (online)

Summary

Acid-treated human plasma is a competitive inhibitor of the hydrolysis of D-Val-Leu-Lys-Nan (S-2251) by plasmin. The rate of hydrolysis is decreased to 50% by 750 fold diluted acidified normal plasma and by 60 fold diluted acidified α2-antiplasmin depleted plasma (α2-antiplasmin concentration less than 2%). These findings suggest that α2-antiplasmin is a contributary but not the main competitive inhibitor of acidified plasma. This interpretation is supported by the finding that α2-antiplasmin depleted plasma reconstituted with purified α2-antiplasmin inhibits the hydrolysis of S-2251 by plasmin at a 125 fold dilution following acidification and by the finding that in a purified system acid inactivated α2-antiplasmin inhibits the hydrolysis of S-2251 by plasmin with a Ki of 25 nM. Thus, besides α2-antiplasmin, other plasma proteins which are at least in part eliminated by the removal of α2-antiplasmin from plasma by immunoadsorption appear to be competitive inhibitors for plasmin in acidified plasma. It is suggested that several competitive inhibitors for plasmin are present and/or generated in acidified plasma and that these inhibitors may at least in part be responsible for the variability in the results of measurements of plasminogen and/or plasmin in plasma following acidification.

 
  • References

  • 1 Collen D. Identification and some properties of a new fast-reacting plasmin inhibitor in human plasma. Eur J Biochem 1976; 69: 209-216
  • 2 Moroi M, Aoki N. Isolation and characterization of alpha2-plasmin inhibitor from human plasma. A novel proteinase inhibitor which inhibits activator-induced clot lysis. J Biol Chem 1976; 251: 5956-5965
  • 3 Müllertz S, Clemmensen I. The primary inhibitor of plasmin in human plasma. Biochem J 1976; 159: 545-553
  • 4 Wiman B, Collen D. Purification and characterization of human antiplasmin, the fast-acting plasmin inhibitor in plasma. Eur J Biochem 1977; 78: 19-26
  • 5 Wiman B, Collen D. On the kinetics of the reaction between human antiplasmin and plasmin. Eur J Biochem 1978; 84: 573-578
  • 6 Wiman B, Boman L, Collen D. On the kinetics of the reaction between human antiplasmin and a low-molecular-weight form of plasmin. Eur J Biochem 1978; 87: 143-146
  • 7 Christensen U, Clemmensen I. Kinetic properties of the primary inhibitor of plasmin from human plasma. Biochem J 1977; 163: 389-391
  • 8 Wiman B, Lijnen HR, Collen D. On the specific interaction between the lysine-binding sites in plasmin and complementary sites in α2-antiplasmin and in fibrinogen. Biochim Biophys Acta 1979; 579: 142-154
  • 9 Alkjaersig N. The purification and properties of human plasminogen. Biochem J 1964; 93: 171-182
  • 10 Deutsch DG, Mertz ET. Plasminogen: purification from human plasma by affinity chromatography. Science 1970; 170: 1095-1096
  • 11 McFarlane AS. Efficient trace-labeling of proteins with iodine. Nature 1958; 182: 53
  • 12 Chase Jr T, Shaw E. Titration of trypsin, plasmin and thrombin with p-nitrophenyl-p’-guanidinobenzoate. HCl. Methods Enzymol 1970; 19: 20-27
  • 13 Wiman B. Affinity-chromatographic purification of human alpha2-antiplasmin. Biochem J 1980; 191: 229-232
  • 14 Edy J, De Cock F, Collen D. Inhibition of plasmin by normal and antiplasmin depleted human plasma. Thromb Res 1976; 8: 513-518
  • 15 Laurell CB. Quantitative estimation of proteins by electrophoresis in agarose gel containing antibodies. Anal Biochem 1966; 15: 45-52
  • 16 Collen D, Lijnen HR, De Cock F, Durieux JP, Loffet A. Kinetic properties of tripeptide lysyl chloromethylketone and lysyl p-nit-roanilide derivatives towards trypsin-like serine proteinases. Biochim Biophys Acta 1980; 165: 158-166
  • 17 Dixon M. The determination of enzyme inhibitor constants. Biochem J 1953; 55: 170-171