Interaction of Plasminogen Activators and Inhibitors with Plasminogen and Fibrin

Lijnen, H. Roger; Collen, D

doi:10.1055/s-2007-1005038

Cited by 115 publications

(55 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Little information on the mechanism by which TC-UK generation is brought about has been obtained. Under the experimental conditions it is likely that plasmin stabilized by fibrin against inhibition by a2-antiplasmin (42) is responsible. However, since pro-UK and t-PA appear to activate different fibrin-bound plasminogens (35), it remains to be shown whether an internal or COOH-terminal lysine-bound plasmin is responsible for the activation of pro-UK.…”

Section: Discussionmentioning

confidence: 99%

Characterization of the intrinsic fibrinolytic properties of pro-urokinase through a study of plasmin-resistant mutant forms produced by site-specific mutagenesis of lysine(158).

Gurewich¹,

Pannell²,

Broeze³

et al. 1988

J. Clin. Invest.

View full text Add to dashboard Cite

Two plasmin-resistant mutant forms of pro-urokinase (pro-UK) constructed by site-directed mutagenesis of Lys'58 to Val'5 and Met'58 were used to evaluate the intrinsic enzymatic and fibrinolytic properties of pro-UK as distinct from those of its two-chain UK (TC-UK) derivative. Both mutants, while resistant to plasmin activation, were as sensitive as pro-UK to degradation by thrombin. Since thrombin cleaves a peptide bond only two residues from the activation site, the integrity of this loop was maintained in the two mutants. The amidolytic and plasminogen-activating activities of the mutants averaged 0.14 and 0.12% that of TC-UK, respectively. The fibrin plate activities were 2,400 JU/ml and 700 1U/mg for the Met'58 and Val"5 mutants or about 1.5% that of TC-UK. These findings attest to a discrete but low intrinsic activity for pro-UK and suggest that the higher values reported in the literature may be related to UK contaminants or plasmin-induced TC-UK generation during the assay. Clot lysis by the mutants required doses > 100-fold higher than those of pro-UK to induce a comparable effect. From this it appears that pro-UK activation is a major determinant of the rate of clot lysis occurring with pro-UK. Clot lysis by the mutants was potentiated by plasmin pretreatment of the fibrin and by the addition of small amounts of TC-UK or tissue plasminogen activator (t-PA). Combinations of t-PA and the mutants were synergistic in their fibrinolytic effects. These findings mirror those previously obtained with pro-UK. We concluded that the previously described potentiation of pro-UK-induced clot lysis by UK or t-PA is mediated primarily by pro-UK itself rather than by a promotion of its activation.

show abstract

Section: Discussionmentioning

confidence: 99%

Characterization of the intrinsic fibrinolytic properties of pro-urokinase through a study of plasmin-resistant mutant forms produced by site-specific mutagenesis of lysine(158).

Gurewich¹,

Pannell²,

Broeze³

et al. 1988

J. Clin. Invest.

View full text Add to dashboard Cite

show abstract

“…The LBS of Plg are critically important in regulating Plg activation (31,32), and in mediating the interaction of plasmin(ogen) with fibrin(ogen) and a2-plasmin inhibitor, as well as with HRGP and the antifibrinolytic amino acids. The kinetics of conversion of Plg to plasmin by TPA are highly unfavorable in the fluid phase.…”

Section: Discussionmentioning

confidence: 99%

Complex formation of platelet thrombospondin with plasminogen. Modulation of activation by tissue activator.

Silverstein¹,

Leung²,

Harpel³

et al. 1984

J. Clin. Invest.

168

View full text Add to dashboard Cite

A bstract. Thrombospondin (TSP), a multifunctional a-granule glycoprotein of platelets, binds fibrinogen, fibronectin, heparin, and histidine-rich glycoprotein and thus may play an important role in regulating thrombotic influences at vessel surfaces. In this study we have demonstrated that purified human platelet TSP formed a complex with purified human plasminogen (Plg). Complex formation was detected by rocket immunoelectrophoresis of mixtures of the purified radiolabeled proteins. Significant complex formation of fluid-phase Plg with adsorbed TSP was also demonstrated by enzyme-linked immunosorbent assay (ELISA). The complex formation was specific, saturable, and inhibited by excess fluid-phase TSP, with an apparent KD of -35 nM. In both ELISA and rocket immunoelectrophoresis systems, complex formation was inhibited by 10 mM eamino-n-caproic acid, implying that there is a role for the lysine binding sites of Plg in mediating the interaction. TSP also formed a complex with plasmin as detected by ELISA but did not directly inhibit plasmin activity measured with a synthetic fluorometric substrate or with a '251-fibrin plate assay. TSP, when incubated with Plg before addition to '25I-fibrin plates significantly inhibited the generation of plasmin activity by tissue plasminogen activator (TPA) in a manner that was calcium dependent. A kinetic study of Plg activation by TPA in the presence of TSP demonstrated that Michaelis-Menten kinetics were followed and that TSP acted as a noncompetitive inhibitor. These studies support the hypothesis that TSP,

show abstract

“…collagen) by activation of metalloproteinases and procollagenases (Pollanen et al 1991). Plasminogen is found in most extracellular fluids and plasma at a concentration of 2(iM, with its main site of production in the liver (Raum et al 1980, Lijnen & Collen 1982. The gene for human plasminogen is located on chromosome 6 and encodes an 810 amino acid, single chain glycoprotein (Murray et al 1987).…”

Section: Plasminogen and Plasminmentioning

confidence: 99%

39 Structure function relationships of plasminogen activator inhibitor type-2 (PAI-2)

1998

Fibrinolysis and Proteolysis

View full text Add to dashboard Cite

Interaction of Plasminogen Activators and Inhibitors with Plasminogen and Fibrin

Cited by 115 publications

References 44 publications

Characterization of the intrinsic fibrinolytic properties of pro-urokinase through a study of plasmin-resistant mutant forms produced by site-specific mutagenesis of lysine(158).

Characterization of the intrinsic fibrinolytic properties of pro-urokinase through a study of plasmin-resistant mutant forms produced by site-specific mutagenesis of lysine(158).

Complex formation of platelet thrombospondin with plasminogen. Modulation of activation by tissue activator.

39 Structure function relationships of plasminogen activator inhibitor type-2 (PAI-2)

Contact Info

Product

Resources

About