Skip to main content
PMC home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1983 May;71(5):1383–1391. doi: 10.1172/JCI110891

Protection of factor Xa from neutralization by the heparin-antithrombin complex.

J M Teitel, R D Rosenberg
PMCID: PMC437002  PMID: 6222069

Abstract

We have studied the accessibility of Factor Xa to neutralization by the heparin-antithrombin complex within plasma and whole blood. This serine protease was detected by measuring the concentrations of activation fragments (F2/F1+2) cleaved from prothrombin. The levels of F2/F1+2) were quantitated by means of a sensitive and specific radioimmunoassay. Our findings indicate that the binding of Factor Xa to "activated" platelets but not to phospholipid micelles results in the protection of the above enzyme from inactivation by the heparin-antithrombin complex. This sequestration of Factor Xa is not affected by the liberation of platelet release proteins or the molecular heterogeneity of the mucopolysaccharide preparations used. The magnitude of enzyme protection is strongly correlated with the extent of prothrombin activation at the time of heparin addition. On this basis, we suggest that high in vivo rates of thrombin generation may lead to the sequestration of Factor Xa on the platelet surface and hence allow this serine protease to resist the action of heparin until the complex is cleared from the circulation.

Full text

PDF

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Dahlbäck B., Stenflo J. Binding of bovine coagulation factor Xa to platelets. Biochemistry. 1978 Nov 14;17(23):4938–4945. doi: 10.1021/bi00616a013. [DOI] [PubMed] [Google Scholar]
  2. Esmon C. T., Owen W. G., Jackson C. M. A plausible mechanism for prothrombin activation by factor Xa, factor Va, phospholipid, and calcium ions. J Biol Chem. 1974 Dec 25;249(24):8045–8047. [PubMed] [Google Scholar]
  3. Harpel P. C., Rosenberg R. D. Alpha 2-macroglobulin and antithrombin-heparin cofactor: modulators of hemostatic and inflammatory reactions. Alpha 2-macroglobulin. Prog Hemost Thromb. 1976;3:145–189. [PubMed] [Google Scholar]
  4. Hök M., Björk I., Hopwood J., Lindahl U. Anticoagulant activity of heparin: separation of high-activity and low-activity heparin species by affinity chromatography on immobilized antithrombin. FEBS Lett. 1976 Jul 1;66(1):90–93. doi: 10.1016/0014-5793(76)80592-3. [DOI] [PubMed] [Google Scholar]
  5. Jordan R. E., Favreau L. V., Braswell E. H., Rosenberg R. D. Heparin with two binding sites for antithrombin or platelet factor 4. J Biol Chem. 1982 Jan 10;257(1):400–406. [PubMed] [Google Scholar]
  6. Kane W. H., Lindhout M. J., Jackson C. M., Majerus P. W. Factor Va-dependent binding of factor Xa to human platelets. J Biol Chem. 1980 Feb 10;255(3):1170–1174. [PubMed] [Google Scholar]
  7. LAURENT T. C. Studies on fractionated heparin. Arch Biochem Biophys. 1961 Feb;92:224–231. doi: 10.1016/0003-9861(61)90341-1. [DOI] [PubMed] [Google Scholar]
  8. Lam L. H., Silbert J. E., Rosenberg R. D. The separation of active and inactive forms of heparin. Biochem Biophys Res Commun. 1976 Mar 22;69(2):570–577. doi: 10.1016/0006-291x(76)90558-1. [DOI] [PubMed] [Google Scholar]
  9. Lau H. K., Rosenberg J. S., Beeler D. L., Rosenberg R. D. The isolation and characterization of a specific antibody population directed against the prothrombin activation fragments F2 and F1 + 2. J Biol Chem. 1979 Sep 25;254(18):8751–8761. [PubMed] [Google Scholar]
  10. Marciniak E. Factor-Xa inactivation by antithrombin. 3. Evidence for biological stabilization of factor Xa by factor V-phospholipid complex. Br J Haematol. 1973 Mar;24(3):391–400. doi: 10.1111/j.1365-2141.1973.tb01662.x. [DOI] [PubMed] [Google Scholar]
  11. Miletich J. P., Jackson C. M., Majerus P. W. Interaction of coagulation factor Xa with human platelets. Proc Natl Acad Sci U S A. 1977 Sep;74(9):4033–4036. doi: 10.1073/pnas.74.9.4033. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Miletich J. P., Jackson C. M., Majerus P. W. Properties of the factor Xa binding site on human platelets. J Biol Chem. 1978 Oct 10;253(19):6908–6916. [PubMed] [Google Scholar]
  13. Miletich J. P., Kane W. H., Hofmann S. L., Stanford N., Majerus P. W. Deficiency of factor Xa-factor Va binding sites on the platelets of a patient with a bleeding disorder. Blood. 1979 Nov;54(5):1015–1022. [PubMed] [Google Scholar]
  14. Rodbard D., Lenox R. H., Wray H. L., Ramseth D. Statistical characterization of the random errors in the radioimmunoassay dose--response variable. Clin Chem. 1976 Mar;22(3):350–358. [PubMed] [Google Scholar]
  15. Rodbard D. Statistical quality control and routine data processing for radioimmunoassays and immunoradiometric assays. Clin Chem. 1974 Oct;20(10):1255–1270. [PubMed] [Google Scholar]
  16. Rosing J., Tans G., Govers-Riemslag J. W., Zwaal R. F., Hemker H. C. The role of phospholipids and factor Va in the prothrombinase complex. J Biol Chem. 1980 Jan 10;255(1):274–283. [PubMed] [Google Scholar]
  17. Rybak M. E., Lau H. K., Tomkins B., Rosenberg R. D., Handin R. I. Relationship between platelet secretion and prothrombin cleavage in native whole blood. J Clin Invest. 1981 Aug;68(2):405–412. doi: 10.1172/JCI110269. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Teitel J. M., Bauer K. A., Lau H. K., Rosenberg R. D. Studies of the prothrombin activation pathway utilizing radioimmunoassays for the F2/F1 + 2 fragment and thrombin--antithrombin complex. Blood. 1982 May;59(5):1086–1097. [PubMed] [Google Scholar]
  19. Tracy P. B., Nesheim M. E., Mann K. G. Coordinate binding of factor Va and factor Xa to the unstimulated platelet. J Biol Chem. 1981 Jan 25;256(2):743–751. [PubMed] [Google Scholar]
  20. Tracy P. B., Peterson J. M., Nesheim M. E., McDuffie F. C., Mann K. G. Interaction of coagulation factor V and factor Va with platelets. J Biol Chem. 1979 Oct 25;254(20):10354–10361. [PubMed] [Google Scholar]
  21. Walker F. J., Esmon C. T. The effects of phospholipid and factor Va on the inhibition of factor Xa by antithrombin III. Biochem Biophys Res Commun. 1979 Sep 27;90(2):641–647. doi: 10.1016/0006-291x(79)91283-x. [DOI] [PubMed] [Google Scholar]
  22. Weiss H. J., Vicic W. J., Lages B. A., Rogers J. Isolated deficiency of platelet procoagulant activity. Am J Med. 1979 Aug;67(2):206–213. doi: 10.1016/0002-9343(79)90392-9. [DOI] [PubMed] [Google Scholar]
  23. Yin E. T. Effect of heparin on the neutralization of factor Xa and thrombin by the plasma alpha-2-globulin inhibitor. Thromb Diath Haemorrh. 1975 Feb 28;33(1):43–50. [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES