Thromb Haemost 1981; 45(03): 219-224
DOI: 10.1055/s-0038-1650174
Original Article
Schattauer GmbH Stuttgart

Secretion of Plasminogen Activators by Cultured Bovine Endothelial Cells: Partial Purification, Characterization and Evidence for Multiple Forms

W E Laug
The Division of Hematology-Oncology, Childrens Hospital of Los Angeles, and University of Southern California School of Medicine, Los Angeles, California, U.S.A.
› Author Affiliations
Further Information

Publication History

Received 09 September 1980

Accepted 18 March 1981

Publication Date:
06 July 2018 (online)

Summary

Endothelial cells were obtained from the aortae of newborn calves and cloned. High plasminogen activator (PA) activity was detected in the supernatant medium and the cell lysates of confluent cultures. The PA activity in the growth medium increased steadily during 12 hrs of incubation, indicating active enzyme secretion by these cells. Sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis of the concentrated medium demonstrated the presence of four plasminogen activators with apparent molecular weights of 77,000 (±3000), 43,000 (±2000), 26,000 (±1500) and 14,500 (±1500) respectively. The 43,000, 26,000 and 14,500 molecular weight forms could be converted to radioactive derivates by active site labeling with 3H diisopropyl fluorophosphate (3H DFP) while the 77,000 Dalton form took up only traces of this radioactively labeled compound. The 43,000 molecular weight form was partially purified by means of salt precipitation and gel filtration. This enzyme preparation activated plasminogen by proteolytic cleavage with maximum activity at pH 7.5-8.5 and demonstrated a specific activity of 80,000 CTA (Committee on Thrombolytic Agents) units/mg protein when tested on 125I-fibrin in the presence of plasminogen. This PA was rapidly and irreversibly inhibited by diisopropyl fluorophosphate (DFP), suggesting that it was a serine protease. The partially purified enzyme was extremely labile at temperatures from 0-60° C, but could be stabilized by lowering the pH to 3 or by the addition of albumin.

 
  • References

  • 1 Tood AS. The histological localization of fibrinolysis activator. J Path Bact 1959; 78: 281-283
  • 2 Sawyer WD, Fletcher AP, Alkjaersig N, Sherry S. Studies on the thrombolytic activity of human plasma. J Clin Invest 1960; 39: 426-434
  • 3 Astrup T, Thorsen S. The physiology of fibrinolysis. Med Clin North Amer 1972; 56: 153-162
  • 4 Aoki N. Preparation of plasminogen activator from vascular trees of human cadavers: Its comparison with urokinase. J Biochem 1974; 75: 731-741
  • 5 Binder BR, Spragg J, Austen KF. Purification and characterization of human vascular plasminogen activator derived from blood vessel perfusates. J Biol Chem 1979; 254: 1998-2003
  • 6 Rijken DC, Wijngaards G, Welbergen J. Relationship between tissue plasminogen activator and the activators in blood and vascular wall. Thromb Res 1980; 18: 815-830
  • 7 Kok P. Separation of plasminogen activators from human plasma and a comparison with activators from human uterine tissue and urine. Thromb Haemostas 1979; 41: 734-744
  • 8 Kaplan AP, Austen KF. The fibrinolytic pathway of human plasma: Isolation and characterization of the plasminogen proactivator. J Exp Med 1972; 136: 1378-1393
  • 9 Kluft C, Trumpi-Kalshoven MM, Jie AF H, Veldhuyzen-Stolk EC. Factor XII-dependent fibrinolysis: A double function of plasma kallikrein and the occurrence of a previously undescribed factor XII- and kallikrein-dependent plasminogen proactivator. Thromb Haemostas 1979; 41: 756-773
  • 10 Jaffe EA, Nachman RL, Becker CG, Minick CR. Culture of human endothelial cells derived from umbilical veins: Identification by morphologic and immunologic criteria. J Clin Invest 1973; 52: 2745-2756
  • 11 Booyse FM, Sedlak BJ, Rafelson ME. Culture of arterial endothelial cells: Characterization and growth of bovine aortic cells. Thrombos Diathes Haemorrh 1975; 34: 825-839
  • 12 Gospodarowicz D, Brown KD, Birdwell CR, Zetter DR. Control of proliferation of human vascular endothelial cells. J Cell Biol 1978; 77: 774-788
  • 13 Buonassisi V, Venter JC. Hormone and neurotransmitter receptors in an established vascular endothelial cell line. Proc Natl Acad Sci USA 1976; 73: 1612-1616
  • 14 Loskutoff DJ, Edgington TS. Synthesis of a fibrinolytic activator and inhibitor by endothelial cells. Proc Natl Acad Sci USA 1977; 74: 3903-3907
  • 15 Laug WE, Tokes ZA, Benedict WF, Sorgente N. Anchorage independent growth and plasminogen activator production by bovine endothelial cells. J Cell Biol 1980; 84: 281-293
  • 16 Rifkin DB, Loeb JN, Moore G, Reich E. Properties of plasminogen activators formed by neoplastic human cell cultures. J Exp Med 1974; 139: 1317-1328
  • 17 White WF, Barlow GH, Mozen MM. The isolation and characterization of plasminogen activators (urokinase) from human urine. Biochemistry 1966; 05: 2160-2169
  • 18 Vetterlein D, Young PL, Bell TE, Roblin R. Immunological characterization of multiple molecular weight forms of human cell plasminogen activators. J Biol Chem 1979; 254: 575-578
  • 19 Dano K, Reich E. Serine enzymes released by cultures neoplastic cells. J Exp Med 1978; 147: 745-757
  • 20 Bernik MB, Rijken DC, Wijngards G. Production of two immunologically distinct plasminogen activators by human tissue in culture. Thromb Haemostas 1979; 42: 414 (abstract).
  • 21 Lowry OH, Rosenbrough NH, Farr AL, Randall RJ. Protein measurement with the folin phenol reagent. J Biol Cheml 1951; 193: 265-275
  • 22 Unkeless J, Dano K, Kellerman GM, Reich E. Fibrinolysis associated with oncogenic transformation. J Biol Chem 1974; 249: 4295-5305
  • 23 Porzio MA, Pearson AM. Improved resolution of myofibrillar proteins with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Biochem Biophys Acta 1977; 490: 27-34
  • 24 Summaria L, Arzadon L, Bernabe P, Robbins KC. The activation of plasminogen to plasmin by urokinase in the presence of the plasmin inhibitor Trasylol. J Biol Chem 1975; 250: 3988-3995
  • 25 Deutsch DG, Mertz ET. Plasminogen: Purification from human plasma by affinity chromatography. Science 1970; 1970: 1095-1096
  • 26 Spragg J, Kaplan AP, Austen KF. The use of isoelectric focusing to study components of the human plasma kinin-forming system. Ann NY Acad Sci 1973; 209: 372-386
  • 27 Mandel Jr R, Kaplan AP. Hageman factor substrates: Human plasma prekallikrein mechanism of activation by Hageman factor and participation in Hageman factor-dependent fibrinolysis. J Biol Chem 1977; 252: 6097-6104
  • 28 Radcliffe R, Heinze T. Isolation of plasminogen activator from human plasma by chromatography on lysine-sepharose. Arch Biochem Biophys 1978; 189: 185-194