Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.6.4 (chondroitinase)
 2,039 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Protein C inhibitor (PCI), also known as plasminogen activator inhibitor 3, inhibits a variety of serine proteases by forming sodium dodecyl sulfate-stable 1:1 complexes. In purified systems PCI is only a weak inhibitor of urokinase. Nevertheless, complexes between PCI and urokinase are found in appreciable amounts in native human urine. Since PCI activity is stimulated by heparin and other glycosaminoglycans, we investigated the presence of stimulating glycosaminoglycans on cells lining the urinary tract. We chose the epithelial kidney tumor cell line TCL-598 as a model and isolated metabolically labeled glycosaminoglycans. TCL-598 incorporated [35S] sulfate into high Mr components (Mr greater than 200,000 and approximately 75,000) as judged from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography of cell extracts; the Mr greater than 200,000 component bound specifically to PCI-Sepharose 4B and was eluted either with heparin (5 mg/ml) or with NaCl (2.0 M). Treatment of this PCI-binding material with chondroitinase ABC, but not with chondritinase AC or heparitinase, abolished binding to PCI-Sepharose, confirming the glycosaminoglycan nature of this material and suggesting the involvement of dermatan sulfate in binding. These glycosaminoglycans eluted from PCI-Sepharose stimulated urokinase inhibition by PCI in a dose-dependent way and enhanced complex formation of 125I-urokinase and PCI as did in control experiments dermatan sulfate from porcine skin and from bovine mucosa. Our results suggest that PCI activity might be regulated also in vivo by the presence or absence of stimulating glycosaminoglycans; dermatan sulfate-containing glycosaminoglycans associated with kidney cells might be responsible for stimulation of the urokinase inhibitory activity of PCI in the urinary tract; the type of glucosaminoclycans might furthermore regulate enzyme specificity of PCI.
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PMID:Urinary protein C inhibitor. Glycosaminoclycans synthesized by the epithelial kidney cell line TCL-598 enhance its interaction with urokinase. 164 16

The amidolytic plasmin activity of a mixture of tissue plasminogen activator (tPA) and plasminogen is enhanced by heparin at therapeutic concentrations. Heparin also increases the activity in mixtures of urokinase-type plasminogen activator (uPA) and plasminogen but has no effect on streptokinase or plasmin. Direct analyses of plasminogen activation by polyacrylamide gel electrophoresis demonstrate that heparin increases the activation of plasminogen by both tPA and uPA. Binding studies show that heparin binds to various components of the fibrinolytic system, with tight binding demonstrable with tPA, uPA, and Lys-plasminogen. The stimulation of tPA activity by fibrin, however, is diminished by heparin. The ability of heparin to promote plasmin generation is destroyed by incubation of the heparin with heparinase, whereas incubation with chondroitinase ABC or AC has no effect. Also, stimulation of plasmin formation is not observed with dextran sulfate or chondroitin sulfate A, B, or C. Analyses of heparin fractions after separation on columns of antithrombin III-Sepharose suggest that both the high-affinity and the low-affinity fractions, which have dramatically different anticoagulant activity, have similar activity toward the fibrinolytic components.
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PMID:Interaction of heparin with plasminogen activators and plasminogen: effects on the activation of plasminogen. 294 15

Binding of urinary protein C inhibitor (PCI) to cultured human epithelial kidney tumor cells (TCL-598) was studied. Binding was dose-dependent, time-dependent, and saturable. Heparin interfered in a dose-dependent way with PCI binding to TCL-598 as did heparan sulfate and to a lesser degree also dermatan sulfate. Pretreatment of TCL-598 with protamine sulfate inhibited subsequent binding of PCI in a dose-dependent manner and > 100 micrograms/ml protamine sulfate reduced binding of PCI to < 10% of the control. Binding of 125I-PCI was specific, and bound 125I-PCI was recovered from the cells by heparin treatment or detached together with intact cells by EDTA treatment, migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with the same mobility (M(r) = 57,000) as unbound 125I-PCI. Furthermore, cell-bound PCI was functionally active as judged from its ability to inhibit the amidolytic activity of urokinase, and its inhibitory activity was stimulated approximately 3-4-fold as compared to fluid-phase PCI. Immunogold electron microscopy revealed that PCI-antigen presented to the cells from the luminal side bound exclusively to that surface in native as well as in prefixed cells. This binding of PCI was abolished in the presence of heparin (50 micrograms/ml) and after pretreatment of the cells either with protamine sulfate (400 micrograms/ml) or with heparinase III (0.5 unit/ml). A slight decrease in PCI binding was seen after pretreatment of the cells with chondroitinase ABC and chondroitinase AC. In contrast, binding of PCI to extracellular matrices of TCL-598 was decreased to approximately 70% after chondroitinase ABC treatment of the extracellular matrices, whereas both heparinase III or chondroitinase AC treatment only reduced matrix-bound PCI to approximately 95%. These data suggest that heparan sulfate-containing proteoglycans are predominantly involved in binding of PCI to the luminal side of TCL-598, while dermatan sulfate-containing proteoglycans, the overall predominant PCI-binding proteoglycans in TCL extracts, are responsible for PCI binding to the extracellular matrix. Heparan sulfate, however, exposed to an environment containing PCI under physiological conditions, might localize PCI and modulate its target enzyme specificity in vivo.
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PMID:Binding of urinary protein C inhibitor to cultured human epithelial kidney tumor cells (TCL-598). The role of glycosaminoglycans present on the luminal cell surface. 818 78

Thrombomodulin (TM), a membrane proteoglycan on endothelial cells, binds thrombin in a 1:1 complex, accelerates the protein C activation by thrombin, promotes the thrombin inactivation by antithrombin III and inhibits the procoagulant properties of thrombin. The inactivation of single-chain urokinase-type plasminogen activator (scu-PA) by thrombin is accelerated about 70-fold by TM [De Munk, Groeneveld and Rijken (1991) J. Clin. Invest. 88, 1680-1684]. The present study investigates the role of the O-linked glycosaminoglycan moiety of TM in the latter reaction. In the presence of an excess of a fully-glycosylated soluble recombinant human TM mutant (high-Mr rec-TM), 0.11 nM thrombin inactivated 50% of 4.4 nM scu-PA in 45 min at 37 degrees C. In the presence of a soluble recombinant TM mutant lacking the glycosaminoglycans (low-Mr rec-TM), 1.9 nM thrombin was needed to inactivate 50% scu-PA, as compared with 4.7 nM thrombin in the absence of TM. Using the scu-PA inactivation assay the dissociation constant for the thrombin-TM interaction was found to be 0.4 nM for high-Mr rec-TM and 14 nM for low-Mr rec-TM. Treatment of high-Mr rec-TM with chondroitinase ABC to digest the glycosaminoglycans decreased the accelerating effect to the level of low-Mr rec-TM. A similar decrease was observed after treatment of solubilized rabbit TM with chondroitinase ABC. As expected, chondroitinase ABC had no influence on the accelerating effect of low-Mr rec-TM. The free glycosaminoglycans obtained by alkaline treatment of TM or chondroitin sulphate A also accelerated the inactivation of scu-PA by thrombin, but about 1000-fold higher concentrations than with TM were needed to obtain the same acceleration. It is concluded that the major glycosaminoglycan of TM plays a pivotal role in the inactivation of scu-PA by the TM-thrombin complex, both in the formation and in the activity of the complex.
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PMID:Role of the glycosaminoglycan component of thrombomodulin in its acceleration of the inactivation of single-chain urokinase-type plasminogen activator by thrombin. 838 42

The aim of using enzymes in vitreoretinal surgery is to facility PVD and create pharmacological vitrectomy. It can be achieved by liquefying the gel structure of the vitreous (synchisis) and weakening of adherence of the posterior vitreous cortex to retina (syneresis). The article reviews currently used enzymes in vitreoretinal surgery (plasmin, hyaluronidase, dispase, chondroitinase, collagenase, urokinase, TPA--tissue plasminogen activator) and presents potential profits and side-effects related to their use. Although the day when vitreous surgery is replaced by pharmacological vitreolisis remains still as a future, these enzymes hold great promise. Additionally it has been proved that enzymes can be used successfully as an intraoperative adjuvant in vitrectomy.
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PMID:[Use of enzyme in vitreoretinal surgery]. 1204 13