Activation of Plasminogen as a Feature in its Assay

Gaffney, P.J.; Brasher, M.; Lord, K. A.; Kirkwood, Tbl

doi:10.1159/000214167

Cited by 8 publications

(7 citation statements)

References 6 publications

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“…The autoproteolysis reaction is retarded by fibrinogen, by ε-aminocaproic acid, by increasing ionic strength, and by glycerol. Although the autoproteolysis reaction involves the breakdown of both the A and B chains of plasmin, it is the breakdown of the B chain that has been suggested to contribute to the irreversible inactivation of the enzyme ( − ).…”

mentioning

confidence: 99%

Regulation of Plasmin Activity by Annexin II Tetramer

et al. 2000

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Annexin II tetramer (AIIt) is a major Ca(2+)-binding protein of the endothelial cell surface which has been shown to stimulate the tissue plasminogen activator (t-PA)-dependent conversion of plasminogen to plasmin. In the present report, we have examined the regulation of plasmin activity by AIIt. The incubation of plasmin with AIIt resulted in a 95% loss in plasmin activity. SDS-PAGE analysis established that AIIt stimulated the autoproteolytic digestion of plasmin heavy and light chains. The kinetics of AIIt-stimulated plasmin autoproteolysis were first-order, suggesting that binding of plasmin to AIIt resulted in the spontaneous autoproteolysis of the bound plasmin. AIIt did not affect the activity of other serine proteases such as t-PA or urokinase-type plasminogen activator. Furthermore, other annexins such as annexin I, II, V, or VI did not stimulate plasmin autoproteolysis. Increasing the concentration of AIIt on the surface of human 293 epithelial cells increased cell-mediated plasmin autoproteolysis. Thus, in addition to stimulating the formation of plasmin, AIIt also promotes plasmin inactivation. These results therefore suggest that AIIt may function to provide the cell surface with a transient pulse of plasmin activity.

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confidence: 99%

Regulation of Plasmin Activity by Annexin II Tetramer

et al. 2000

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“…Its active center is localized on the light (25 kD) chain [39], which is degraded during autolysis into 16 kD und 8 kD fragments, with a loss of enzymatic activity [41]. For a possible clinical use, ensuring stability of the isolated enzyme is thus crucial.…”

Section: In Vitro Studiesmentioning

confidence: 99%

A disposable system for rapid purification of autologous plasmin as an adjunct to vitrectomy — performance and safety profile

Hermel

Dailey

Trese

et al. 2010

Graefes Arch Clin Exp Ophthalmol

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“…Concentrations of fibrinogen in plasma were measured by the sodium sulfite precipitation method (11). Concentration of o2-antiplasmin (u-2-AP) in sample plasma was calculated from the extent of inhibition of exogenous plasmin (0.3 cu/ml in PBS with 25% glycerol, Kabi-Vitrum, Stockholm, Sweden) assayed spectrophotometrically with the plasmin specific chromogenic substrate 3-2251 (Kabi-Vitrum) (12). Siandard curves .for assay of a-2-AP were constructed with pooled human plasma from 10 normal subjects.…”

Section: Effects Of T-pa and Scu-pa On Concentrations Of Fibrinogen Amentioning

confidence: 99%

The Nature of Synergy between Tissue-Type and Single Chain Urokinase-Type Plasminogen Activators

1989

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SummaryEnhancement of thrombolysis with combinations of tissue-type and single chain urokinase plasminogen activators (t-PA and scu-PA) has been demonstrated in vivo but has not been seen consistently in vitro. This study was designed to characterize interactions between t-PA and scu-PA with respect to rate of and extent of thrombolysis in vitro and to delineate mechanisms responsible. Combinations of t-PA and scu-PA at selected concentrations synergistically enhanced thrombolysis in vitro compared with thrombolysis induced by either activator alone. Enhanced thrombolysis did not occur at the expense of fibrin specificity since the extent of fibrinogenolysis and consumption of α2-antiplasmin were significantly less with synergistic combinations of t-PA and scu-PA compared with equi-effective concentrations of either activator alone. Attenuation of complex formation of t-PA and two chain u-PA (tcu-PA), formed from scu-PA, with plasma proteins did not appear to contribute to enhancement of thrombolysis as assessed by fibrin autography. Binding of 125I-t-PA to thrombi was increased by 27% at 1 hr and by 21% at 2 hr in the presence of scu-PA (p <0,001 for both). Conversion of scu-PA to tcu-PA was enhanced when thrombi were exposed to scu-PA in the presence of t-PA. Results of this study indicate that t-PA and scu-PA at selected concentrations enhance thrombolysis in vitro synergistically without compromising fibrin specificity. Enhanced binding of t-PA to thrombi in the presence of scu-PA and enhanced conversion of scu-PA to tcu-PA appear to contribute to synergy between t-PA and scu-PA for thrombolysis.

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Activation of Plasminogen as a Feature in its Assay

Cited by 8 publications

References 6 publications

Regulation of Plasmin Activity by Annexin II Tetramer

Regulation of Plasmin Activity by Annexin II Tetramer

A disposable system for rapid purification of autologous plasmin as an adjunct to vitrectomy — performance and safety profile

The Nature of Synergy between Tissue-Type and Single Chain Urokinase-Type Plasminogen Activators

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