Studies of an Inhibitor of the Thrombin-Fibrinogen Reaction Localized in Rat Liver Microsomes. Interference with the Polymerization Step

Summary

A heat-stable, macromolecular inhibitor of the thrombin-fibrinogen reaction localized in rat liver microsomes has been shown to interfere with the polymerization step in the fibrinogen-fibrin conversion. The inhibitor had no effect on thrombin activity as measured with the synthetic, chromogenic substrate Bz-Phe-Val-Arg-pNA. The amount of fibrin formed and the release of fibrinopeptide A were not affected by the inhibitor. Recording of turbidity at 350 nm and 600 nm indicated an inhibition of the lateral aggregation of the end-to-end fibrin polymers. The inhibitor was localized in both the luminal and membrane fractions of the microsomes. The inhibitor activity was not affected by warfarin treatment of the rats.

• References

• 1 Abildgaard U. 1964; Acceleration of fibrin polymerization by acetate and other low molecularions. Scandinavian Journal of Clinical and Laboratory Investigation 16: 521.
• 2 Doolittle R. F. 1973; Structural aspects of the fibrinogen to fibrin conversion. Advances in Protein Chemistry 27: 1.
• 3 Edsall J. T, Lever W. F. 1951; Effects of ions and neutral molecules on fibrin clotting. Journal of Biological Chemistry 191: 735.
• 4 Ferry J. D, Morrison P. R. 1947; Preparation and properties of serum and plasma proteins. VIII. The conversion of human fibrinogen to fibrin under various conditions. Journal of the American Chemical Society 69: 388.
• 5 Flengsrud R, Østerud B, Prydz H. 1972; Inhibition of the thrombin-fibrinogen reaction by a macromolecular factor from rat liver. Biochemical Journal 129: 83.
• 6 Godal H. C. 1961; Simple syneresis procedure for fibrinogen assay. Scandinavian Journal of Clinical and Laboratory Investigation 13: 530.
• 7 Helgeland L, Christensen T. B, Janson T. L. 1972; The distribution of protein-bound carbohydrates in submicrosomal fractions from rat liver. Biochimica Biophysica Acta 286: 62.
• 8 Helgeland L. 1975; On the presence of a heat-stable, macromolecular inhibitor of the thrombin-fibrinogen reaction in rat liver microsomes and its separation from prothrombin. Biochimica Biophysica Acta 386: 203.
• 9 Herzig R. H, Ratnoff O. D, Shainoff J. R. 1970; Studies on a procoagulant fraction of southern copperhead snake venom: The preferential release of fibrinopeptide B. Journal of Laboratory and Clinical Medicine 76: 451.
• 10 Janson T. L, Helgeland L. 1975; Biological and immunological activity of prothrombin in rough and smooth microsomes isolated from rat liver. Biochimica Biophysica Acta 379: 598.
• 11 Laurent T. C, Blombäck B. 1958; On the significance of the release of two different peptides from fibrinogen during clotting. Acta Chemica Scandinavica 12: 1875.
• 12 Lowry O. H, Rosebrough N. J, Farr A. L, Randall R. J. 1951; Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193: 265.
• 13 Mosesson M. W, Alkjaersig N, Sweet B, Sherry S. 1967; Human fibrinogen of relatively high solubility. Comparative biophysical, biochemical, and biological studies with fibrinogen of lower solubility. Biochemistry 6: 3279.
• 14 Sletten K, Dus K, deKlerk H, Kamen M. D. 1968; Cytochrome c₂ of Rhodospirillum rubrum. I. Molecular properties of the protein and amino acid sequences of its peptides derived by the action of trypsin and thermolysin. Journal of Biological Chemistry 243: 5492.
• 15 Suttee J. W. 1973; Mechanism of action of vitamin K: Demonstration of a liver precursor of prothrombin. Science 179: 192.
• 16 Svendsen L, Blombäck B, Blombäck M, Olsson P. I. 1972; Synthetic chromogenic substrates for the determination of trypsin, thrombin and thrombin-like enzymes. Thrombosis Research 1: 267.
• 17 Ødegård O. R, Lie M, Abildgaard U. 1975; Heparin cofactor activity measured with an amidolytic method. Thrombosis Research 6: 287.