Fibrinogenic activity

Blomback, B., Carlsson, K., Fatah, K., Hessel, B., and Procyk, R. (1994). Fibrin in human plasma Gel architectures governed by rate and nature of fibrinogen activation. Thromb. Res. 75, 521-538. 

Specific lysine residues of antithrombin III bind heparin to act as a major inhibitor of serine-protease plasma coagulation factors. Nonenzymatic glycosylation of antithrombin III, by preferentially binding to lysines and decreasing the affinity of antithrombin III for heparin, will decrease its thrombin inhibitory activity (B3I, C7). In vivo inhibition of antithrombin III occurs in type I diabetics (D27, S35). Decreased antithrombin III and fibrinogen activity in severe diabetics can be reversed by heparin infusion. 

Belisario MA, Di Domenico C, Pelagalli A, Della MR, Staiano N. Metal-ion catalyzed oxidation affects fibrinogen activity on platelet aggregation and adhesion. Biochimie 1997 79 449-55. 

With regard to the fibrinogenic activity of yttrium compounds, the American Conference of Governmental Industrial Hygienists (ACGIH 2003) currently recommends a threshold limit value (TLV) of 1 mg m for yttrium metal and its compounds when measured as yttrium. 

Removal of the first 16 residues of Aa-fibrinogen activates fibrinogen for fibrin formation by removing the repulsive effect of four negative charges of carboxylates, -COO", from two glutamic acid (Glu, E) and two aspartic... 

II Prothrombin Hydrolyses fibrinogen Activates Factors XIII, V, Hypoprothrombinaemia... 

An enzyme present in blood which lyses fibrin and fibrinogen. Activators such as tr3q)sin convert the inactive precursor plasminogen into plasmin. 

Thrombin, the two-chain derivative of the prothrombin molecule, has a molecular weight of approximately 37,000 daltons. Its proteolytic properties induce the conversion of fibrinogen to fibrin to produce the initial visible manifestation of coagulation, the soluble fibrin clot. In addition, thrombin influences the activity of Factors V, VIII, and XIII and plasmin. Thrombin affects platelet function by inducing viscous metamorphosis and the release reaction with subsequent aggregation. 

Factor II. Prothrombin is a vitamin K-dependent compound synthesized by the Hver. When prothrombin is activated it is cleaved at two sites, resulting in a two-chain molecule linked by a disulfide bond that has a molecular weight of 37,000 daltons. Thrombin is the serine protease that initiates the conversion of soluble fibrinogen into fibrin. 

Tissue Plasminogen Aetivator (tPA). While streptokinase and urokinase can effectively induce clot dissolution in the majority of patients if given early, they lack clot specificity. Treatment with these enzymes results in a systemic lytic state attributable to their degradative action on circulating fibrinogen. Tissue plasminogen activator (tPA) was developed to achieve rapid and specific thrombolysis. 

FIGURE 15.5 The cascade of activation steps leading to blood clotting. The intrinsic and extrinsic pathways converge at Factor X, and the final common pathway involves the activation of thrombin and its conversion of fibrinogen into fibrin, which aggregates into ordered filamentous arrays that become cross-linked to form the clot. 

The hydantoin moiety has been utilized as a biostere for the peptide linkage, transforming a peptide lead into an orally available drug candidate. Therefore, an Arg-Gly-Asp-Ser tetrapeptide (18) lead structure was modified to a non-peptide RGD mimetic as an orally active fibrinogen receptor antagonist 19. ° ... 

Most antiplatelet dtugs only partially inhibit platelet activation. In contrast, blockers of GPIIb/llla interfere at the end of the pathway common to platelet aggregation. They prevent fibrinogen and vWf from... 

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