Proteolysis Of Fibrinogen Research Articles

Inhibition of the fibrinogen-plasmin reaction by ω-aminocarboxylic acids and alkylamines

Abstract We measured (with the pH stat) the rat of hydrolysis of fibrinogen and lysine methyl ester by plasmin (EC 3.4.4.1.4) and calculated the maximal velocity (vmax) for both reactions. The vmax for the lysine methyl ester-plasmin reaction is 1.5 times greater than the vmax for the fibrinogen-plasmin reaction at pH 7.0, and at 23°. The same enzyme preparation and solvent ionic strength were used in both reactions. A new method for measuring proteolysis of fibrinogen by plasmin is reported. This method is based on the precipitation of non-hydrolyzed fibrinogen by 9% ethanol. With this method we investigated inhibition of the fibrinogen-plasmin reaction by ω-aminocarboxylic acids and analogues of some of the 3,4,5 and 6-carbon members. Glycine, β-alanine, γ-aminobutyric acid, glutaric acid, valeric acid, cadaverine and lysine did not inhibit with concentrations less than 10 mM (Ki>10 mM). Competitive inhibition was found with δ-aminovaleric acid (Ki = 4.7 mM), ϵ-aminocaproic acid (Ki = 2.8 mM), ω-aminocaprylic acid (Ki = 1.0 mM), propylamine (Ki = 3.3 mM)

THE ACTION OF PLASMIN ON FIBRINOGEN ADN FIBRIN. I. CHANGES IN THE N-TERMINAL RESIDUES.

Changes in the N-terminal amino acids of bovine and human fibrinogen and fibrin resulting from the action of plasmin (EC 3.4.4..14) on these protinens have been studied. Only the N-terminal amino acids of those protein fractions whose phenylthiocarbamyl derivatives are insoluble in acetone-water have been measured. Plasminolysis of the bovine and human proteins leads to similarities and differences in the relative rates at which N-termnial residues appear. Possible causes for these differences are discussed. The observations explain in part the presence of extraneous N-terminal residues frequently found in fibrinogen, particularly if isolated from aged Fraction I preparations, and provide preliminary information which may be useful as a guide during the separation of fragments formed during the proteolysis of fibrinogen.

CHEMISTRY AND PHYSIOLOGY OF THE FIBRINOGEN-FIBRIN TRANSITION.

ArticlesChemistry and Physiology of the Fibrinogen-Fibrin TransitionK. Laki, and J. A. GladnerK. Laki, and J. A. GladnerPublished Online:01 Apr 1964https://doi.org/10.1152/physrev.1964.44.2.127MoreSectionsPDF (5 MB)Download PDF ToolsExport citationAdd to favoritesGet permissionsTrack citations ShareShare onFacebookTwitterLinkedInWeChat Back to Top Next Download PDF FiguresReferencesRelatedInformation Cited ByThrombin is a potent mitogen for rat astroblasts but not for oligodendroblasts and neuroblasts in primary cultureInternational Journal of Developmental Neuroscience, Vol. 5, No. 3The release of small amounts of fibrinopeptide-b (FPB) is of critical importance for the thrombin clotting timeThrombosis Research, Vol. 42, No. 4Polymerization properties of two normally circulating fibrinogens, HMW and LMW. Evidence that the COOH-terminal end of the a-chain is of importance for fibrin polymerizationThrombosis Research, Vol. 39, No. 5Fibrinogen — fibrin transformation: 2. Influence of temperature, pH and of various enzymes on the intermediate structuresInternational Journal of Biological Macromolecules, Vol. 3, No. 1Lower susceptibility of human des-AA versus des-AABB fibrin towards fibrin stabilizing factorThrombosis Research, Vol. 13, No. 5[14] ThrombinFibrinogen Concentration and Immunoelectrophoresis in the Internal Jugular Vein and the Corresponding Arterial Blood in Ischemic Brain AfflictionsStroke, Vol. 4, No. 5The molecular and functional condition of plasma fibrinogen during thrombolytic therapy with streptokinase (SK)Thrombosis Research, Vol. 2, No. 2Coagulant and esterase activities of thrombin and Bothrops atrox venomToxicon, Vol. 10, No. 6On the quaternary structure of human thrombinClinica Chimica Acta, Vol. 34, No. 3Formation of highly ordered polymers from fibrinogen and fibrin degradation productsBiochimica et Biophysica Acta (BBA) - Protein Structure, Vol. 221, No. 2[9a] Bovine prothrombin and thrombinNonenzymatic polymerization of fibrinogen by protamine sulfate An electron microscope studyBiochimica et Biophysica Acta (BBA) - Protein Structure, Vol. 194, No. 2A Light and Electron Microscopic Study of Arteries and Other Tissues From Dogs Subjected To Chronic Fibrinolytic Inhibition With Amcha18 August 2016 | Vascular Surgery, Vol. 2, No. 3The biological properties of peptides derived from fibrinogenBiochemical Pharmacology, Vol. 17Acute Vascular Endothelial Changes Associated with Increased Blood Velocity GradientsCirculation Research, Vol. 22, No. 2High molecular weight products of the late stage of fibrinogen proteolysis by plasmin and their structural relation to the fibrinogen moleculeBiochimica et Biophysica Acta (BBA) - Protein Structure, Vol. 147, No. 2Pulmonary and Circulatory Effects of FibrinopeptidesCirculation Research, Vol. 21, No. 4Enzymic lysis of plasma clots: The influence of fibrin stabilization on lysis ratesArchives of Biochemistry and Biophysics, Vol. 120, No. 3Isolation of coagulant and anticoagulant principles from the venom of Agkistrodon acutusToxicon, Vol. 4, No. 4Sensitivity of thrombin and autoprothrombin C to selected enzyme inhibitorsLife Sciences, Vol. 4, No. 4 More from this issue > Volume 44Issue 2April 1964Pages 127-160 https://doi.org/10.1152/physrev.1964.44.2.127PubMed14152903History Published online 1 April 1964 Published in print 1 April 1964 Metrics

A rapid enzymatic method for assay of fibrinogen fibrin polymerization time (FPT test)

A quantitative enzymatic fibrinogen assay can be based on kinetic data for the conversion of fibrinogen to fibrin in the presence of thrombin. The 2 essential conditions are: a critically low substrate range and a good quality enzyme source, whose activity should be high enough to reduce the fibrinogen proteolysis time to a constant minimum. The 2 reagents corresponding to these criteria are extensively discussed. The preparation of a standard curve, the reproducibility of results and arguments for expressing in clinical practice the fibrinogen content in terms of whole blood rather than plasma are discussed. The FPT test is also suggested as a capillary blood method for fibrinogen assay.

Inhibition of fibrin polymerization by fibrinogen proteolysis products.

The action of fibrinogen proteolysis products in inhibiting fibrinogen-fibrin conversion by thrombin has excited considerable interest because of its possible significance in blood coagulation. This reaction has been investigated by following the polymerization of highly purified fibrin monomer, in the presence and absence of fibrinogen proteolysis products, by a spectrophotometric procedure. Fibrinogen proteolysis products inhibited polymerization at low ratios of proteolysis products/monomer, and both early and late phases of polymerization were equally affected. Polymerization rates of fibrin monomer, as apart from the gel point, were little influenced by reaction temperature over the range 15–35 C, and the degree of inhibition produced by fibrinogen proteolysis products was likewise independent of temperature. A linear relationship was demonstrated between the degree of inhibition to polymerization and the ratio of fibrinogen proteolysis products to monomer. It is suggested that the inhibitory mechanism involves the coupling of fibrinogen proteolysis products with monomer in a "competitive" manner.

Pathogenesis of the coagulation defect developing during pathological plasma proteolytic ("fibrinolytic") states. I. The significance of fibrinogen proteolysis and circulating fibrinogen breakdown products.

Pathogenesis of the coagulation defect developing during pathological plasma proteolytic ("fibrinolytic") states. I. The significance of fibrinogen proteolysis and circulating fibrinogen breakdown products.

Mechanism of clot lysis.

THE availability of a large number of inhibitors of proteolytic enzymes, as well as the availability of highly purified streptokinase, plasminogen and plasmin, suggested to me the investigation of the nature of the enzyme or enzymes capable of dissolving fibrin clots. Proteolytic enzymes in general, but more particularly trypsin and chymotrypsin, are known for their ability to digest fibrin clots; certain snake venoms can also do this. The proteolysis of fibrinogen and fibrin by venoms, trypsin or plasmin appears to vary, depending upon which of the enzyme is used. The clotting of fibrinogen is the result of the splitting of an arginine peptide bond in the fibrinogen molecule1; this tends to produce a product (fibrin) which is much less susceptible to hydrolysis by trypsin and venoms than the parent substance, fibrinogen2,3. Fibrin, on the other hand, is as sensitive to plasmin as is fibrinogen3.

Dysproteinemia Induced in Vitro by Plasmin Digestion of Fibrinogen

Abstract 1. Electrophoretic investigation of split products of plasmin digestion of pure fibrinogen and of fibrinogen in a plasma medium was performed. It was shown that split products possessed electrophoretic mobilities of alpha, beta and gamma globulins. 2. It could be shown that by digestion of I131-labeled fibrinogen, radioactivity in the range of alpha, beta and gamma globulins is released. 3. Simultaneously with the formation of high molecular intermediates, low molecular, TCA-soluble substances are released. 4. Radioactivity balance calculation of the relative amounts of the newly formed fractions has been performed. 5. A possible influence of plasmin-induced fibrinogen proteolysis on the electrophoretic pattern of plasma proteins in dysproteinemia has been suggested. 6. The electrophoretic pattern of plasma proteins, obtained in the above experiments is similar to those seen in patients with dysproteinemia.

Effect of divalent cations on proteolysis of fibrinogen.

SummaryThe effects of various divalent cations on proteolysis of fibrinogen by trypsin and chymotrypsin were studied. Calcium, Mg, Mn, Co, Zn, and Cd were approximately equally effective in reducing the rate of proteolysis by trypsin. At levels as low as 10-7 M, Ca began to decrease the rate of proteolysis by either trypsin or chymotrypsin, and a 50% reduction of the rate occurred at about 10-3 M. The effects of Ca on both tryptic and chymotryptic digestion appeared to yield the kinetics of a competitive inhibition; and the suggestion is made that Ca acts to affect an equilibrium between two forms of fibrinogen, the one susceptible, the other inhibitory, to proteolysis.

Relation between degree of fibrinogen proteolysis by plasmin and fibrinolytic paracoagulation.

SummaryFibrinogen proteolysis by plasmin and the clotting of lysed fibrinogen were studied. Close relationship was found between increase in NPN and behavior of lysed fibrinogen.