Effect of fucoidan during activation of human plasminogen

Doctor, V. M.; Hill, C.; Jackson, G. J.

doi:10.1016/0049-3848(95)00111-4

Cited by 20 publications

(10 citation statements)

References 24 publications

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“…Activation of Glu-Plg by t-PA was reported [32] to be enhanced in a synergistic manner when fucoidan was added in conjunction with 6-AH. The stimulating effect of 6-AH on Glu-Plg activation was reported [28][29][30] to be due to the change in gross conformation induced by binding of the amino acid to one or more weak binding sites of Glu-Plg.…”

Section: Discussionmentioning

confidence: 97%

The effect of fucoidan, heparin and cyanogen bromide-fibrinogen on the activation of human glutamic-plasminogen by tissue plasminogen activator

Bell

Duhon²,

Doctor³

2003

Blood Coagulation & Fibrinolysis

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Earlier studies on the stimulatory effect of fucoidan, heparin, and cyanogen bromide (CNBr)-fibrinogen digest on the in-vitro activation of glutamic type plasminogen by tissue plasminogen activator, which were performed using subphysiologic ionic strengths of buffers, gave inconsistent results because of the variation in the ionic strengths of the buffers used. Studies were therefore conducted on the effect of these cofactors using 0.05 mol/l Tris buffer containing a physiologic concentration of sodium chloride. The double reciprocal plots of the activation of glutamic type plasminogen by tissue plasminogen activator in the presence of fucoidan and 6-aminohexanoic acid (6-AH) or heparin and 6-AH showed a four- to six-fold increase in K(cat), while the K(m) remained unchanged. On the other hand, there was greater than six-fold lowering of K(m) from 0.213 to 0.035 micromol/l in the presence of CNBr-fibrinogen, while K(cat) was only slightly increased. The ratios of the initial rate of plasmin generation in the presence or absence of the cofactors were plotted against the inverse of the volume fraction of glutamic type plasminogen or of tissue plasminogen activator after serial dilution. The results suggested that the enhancements by fucoidan and 6-AH or CNBr-fibrinogen were due to their interactions directed towards glutamic type plasminogen, while for heparin and 6-AH, the interaction was directed towards tissue plasminogen activator. Circular dichroism studies in the near ultraviolet range (250-308 nm) showed that 6-AH enhanced the circular dichroism spectra of glutamic type plasminogen around certain chromophores, while fucoidan and heparin had no effect, suggesting that the enhancement by the cofactors may be related to the favorable conformational changes of glutamic type plasminogen by 6-AH.

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Section: Discussionmentioning

confidence: 97%

The effect of fucoidan, heparin and cyanogen bromide-fibrinogen on the activation of human glutamic-plasminogen by tissue plasminogen activator

Bell

Duhon²,

Doctor³

2003

Blood Coagulation & Fibrinolysis

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“…The complete primary sequence of streptokinase (13) and its crystal structure (14) have been published. Heparin oligosaccharides,fucoidan and 6-AH are reported to inhibit the activation of Glu-Plg by streptokinase (5,6) and the inhibition by heparin oligosaccharideswas reversed by divalent cations (5). The inhibition by 6-AH of plasminogen to plasmin conversion by streptokinase was postulated as involving the formation of plasminogen-6-AH complex that, due to the altered conformation of plasminogen, was not acted on by streptokinase (8).…”

Section: Discussionmentioning

confidence: 99%

“…Heparin derived oligosaccharides, 6-aminohexanoic acid (6-AH) and fucoidan are reported to inhibit the activation of glutamic plasminogen (Glu-Plg) by streptokinase, while addition of divalent cations reversed the inhibition by heparin oligosaccharides (5)(6)(7)(8). Inclusion of chloride ions in isotonic buffers was reported to inhibit the activation of Glu-Plg by streptokinase (9), while a reciprocal effect of 6-AH and chloride ions was reported during the activation of human Glu-Plg by human urokinase (10).…”

Section: Introductionmentioning

confidence: 99%

Ionic modulation of the effects of heparin and 6-aminohexanoic acid on plasminogen activation by streptokinase: The role of ionic strength, divalent cations and chloride

Guinn

Johnson

Doctor

2003

Eur. J. Drug Metab. Pharmacokinet.

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Studies were conducted on the effect of heparin or 6-aminohexanoic acid (6-AH) on the activation of glutamic plasminogen (Glu-Plg) by streptokinase in the presence of different concentrations of buffer, NaCl and divalent cations. Heparin and 6-AH inhibited streptokinase-mediated activation of Glu-Plg using 10 mM Tris-HCl buffer pH 7.4. This inhibition was partially reversed by the addition of 0.2-1.0 mM of Mg ions. Increasing the ionic strength of Tris-HCl buffer from 10 to 50 mM or addition of 50-150 mM of NaCl to 50 mM Tris-HCl pH 7.4 inhibited the activation of Glu-Plg by streptokinase while decreasing the % inhibition by heparin over the control samples. Double reciprocal plot of the activation of Glu-Plg by streptokinase using 50 mM Tris-HCl pH 7.4 containing 100 mM NaCl showed that the addition of heparin lowered Vmax by 50% without affecting Km. To determine whether the inhibitory effect of heparin was specifically directed towards Glu-Plg or streptokinase, the ratios of the initial rate of plasmin generation in the presence of heparin over the controls were plotted against the inverse of the volume fraction of Glu-Plg or streptokinase after serial dilutions. The results indicated that the dilutions of streptokinase but not of Glu-Plg influenced the ratios, suggesting an interaction of heparin with streptokinase. Addition of 6-AH reversed the inhibitory effect of NaCl on the activation of Glu-Plg by streptokinase and the results of the near UV CD spectra of Glu-Plg showed that addition of 6-AH enhanced the spectra in this region with an increase in the ellipticity which was not affected by addition of NaCl.

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“…dose of 200 mg of hemovasal, a glycosaminoglycan belonging to the family of heparan sulfates, showed a greater increase in t-PA and a considerable diminution of the activity of PAI-l over a 24 h period in post-myocardial infarction patients (21). In vitro activation of Glu-Plg by t-PA was reported (19) to be enhanced in a synergistic manner when fucoidan was added in conjunction with 6-AH. Kinetic studies using double reciprocal plot showed that K m value for this interaction, in the presence of fucoidan-6-AH, was not affected but the K cat was enhanced 5-fold (20).…”

Section: Enhancement Of the Activation Of Glu-plg By T·pa In The Presmentioning

confidence: 99%

“…In a recent study, a highly sulfated semisynthetic fucoidan was reported to stimulate t-PA induced plasma clot lysis by protecting plasmin activity from Uz-antiplasminand by decreasing the rate of polymer formation (18). In conjunction with 6-aminohexanoic acid (6-AH), fucoidan was reported (19) to enhance the activation of Glu-Plg by t-PA in a synergistic manner and fucoidan alone at higher concentrations was effective in enhancing the activation of Glu-Plg by urokinase. Enzyme kinetic studies on the role of fucoidan during the activation of Glu-Plg by urokinase showed a decrease in K m by 50% and an increase in K cat by 30-fold, while the addition of fucoidan and 6-AH during the activation of Glu-Plg by t-PA showed a 5-fold increase in K cat without affecting K m (20).…”

Section: Introductionmentioning

confidence: 99%

Mechanism of enhancement by fucoidan and CNBr-fibrinogen digest of the activation of glu-plasminogen by tissue plasminogen activator

Muneer

Bell

Doctor

2000

Eur. J. Drug Metab. Pharmacokinet.

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The interactions of fucoidan with human glutamic type plasminogen (Glu-Plg), porcine pancreatic elastase digested plasminogen fractions and two chain tissue plasminogen activator t-PA) were investigated using fucoidan-Sepharose affinity chromatography. The results showed a high degree of affinity between fucoidan-Sepharose and Glu-Plg or PlgK(1-3) but not with PlgK4 or mini-Plg. Fucoidan-Sepharose also showed a high affinity for t-PA, which was largely reversed by 0.002 M 6-aminohexanoic acid (6-AH). The addition of fucoidan and CNBr-fibrinogen digest (CNBr-Fbg) gave the highest enhancement of the in vitro activation of Glu-Plg by t-PA in the presence of 0.002 M 6-AH. The results of affinity chromatography and enhancement studies suggested a template mechanism, since increasing the concentrations of any one of the two cofactors reversed the enhancement. Enzyme kinetic studies, using double reciprocal plots, showed that the addition of fucoidan-6-AH increased Kcat by 7-fold without affecting Km and addition of CNBr-Fbg lowered Km by 5-fold without significantly affecting Kcat while addition of the two cofactors lowered Km by 16-fold without significantly affecting Kcat. The enhancement by fucoidan-6-AH or by CNBr-Fbg of the in vitro activation of Glu-Plg by t-PA was reversed by plasminogen activator inhibitor 1 (PAI-1). Fucoidan-Sepharose affinity chromatography revealed that the binding of PAI-1 with fucoidan may be responsible for the reversal of the enhancement by fucoidan-6-AH.

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Effect of fucoidan during activation of human plasminogen

Cited by 20 publications

References 24 publications

The effect of fucoidan, heparin and cyanogen bromide-fibrinogen on the activation of human glutamic-plasminogen by tissue plasminogen activator

The effect of fucoidan, heparin and cyanogen bromide-fibrinogen on the activation of human glutamic-plasminogen by tissue plasminogen activator

Ionic modulation of the effects of heparin and 6-aminohexanoic acid on plasminogen activation by streptokinase: The role of ionic strength, divalent cations and chloride

Mechanism of enhancement by fucoidan and CNBr-fibrinogen digest of the activation of glu-plasminogen by tissue plasminogen activator

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